Remove the review bot app.

reviewbot/third_party/google-api-python-client/gflags.py

-#!/usr/bin/env python
-#
-# Copyright (c) 2002, Google Inc.
-# All rights reserved.
-#
-# Redistribution and use in source and binary forms, with or without
-# modification, are permitted provided that the following conditions are
-# met:
-#
-#     * Redistributions of source code must retain the above copyright
-# notice, this list of conditions and the following disclaimer.
-#     * Redistributions in binary form must reproduce the above
-# copyright notice, this list of conditions and the following disclaimer
-# in the documentation and/or other materials provided with the
-# distribution.
-#     * Neither the name of Google Inc. nor the names of its
-# contributors may be used to endorse or promote products derived from
-# this software without specific prior written permission.
-#
-# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-#
-# ---
-# Author: Chad Lester
-# Design and style contributions by:
-#   Amit Patel, Bogdan Cocosel, Daniel Dulitz, Eric Tiedemann,
-#   Eric Veach, Laurence Gonsalves, Matthew Springer
-# Code reorganized a bit by Craig Silverstein
-
-"""This module is used to define and parse command line flags.
-
-This module defines a *distributed* flag-definition policy: rather than
-an application having to define all flags in or near main(), each python
-module defines flags that are useful to it.  When one python module
-imports another, it gains access to the other's flags.  (This is
-implemented by having all modules share a common, global registry object
-containing all the flag information.)
-
-Flags are defined through the use of one of the DEFINE_xxx functions.
-The specific function used determines how the flag is parsed, checked,
-and optionally type-converted, when it's seen on the command line.
-
-
-IMPLEMENTATION: DEFINE_* creates a 'Flag' object and registers it with a
-'FlagValues' object (typically the global FlagValues FLAGS, defined
-here).  The 'FlagValues' object can scan the command line arguments and
-pass flag arguments to the corresponding 'Flag' objects for
-value-checking and type conversion.  The converted flag values are
-available as attributes of the 'FlagValues' object.
-
-Code can access the flag through a FlagValues object, for instance
-gflags.FLAGS.myflag.  Typically, the __main__ module passes the command
-line arguments to gflags.FLAGS for parsing.
-
-At bottom, this module calls getopt(), so getopt functionality is
-supported, including short- and long-style flags, and the use of -- to
-terminate flags.
-
-Methods defined by the flag module will throw 'FlagsError' exceptions.
-The exception argument will be a human-readable string.
-
-
-FLAG TYPES: This is a list of the DEFINE_*'s that you can do.  All flags
-take a name, default value, help-string, and optional 'short' name
-(one-letter name).  Some flags have other arguments, which are described
-with the flag.
-
-DEFINE_string: takes any input, and interprets it as a string.
-
-DEFINE_bool or
-DEFINE_boolean: typically does not take an argument: say --myflag to
-                set FLAGS.myflag to true, or --nomyflag to set
-                FLAGS.myflag to false.  Alternately, you can say
-                   --myflag=true  or --myflag=t or --myflag=1  or
-                   --myflag=false or --myflag=f or --myflag=0
-
-DEFINE_float: takes an input and interprets it as a floating point
-              number.  Takes optional args lower_bound and upper_bound;
-              if the number specified on the command line is out of
-              range, it will raise a FlagError.
-
-DEFINE_integer: takes an input and interprets it as an integer.  Takes
-                optional args lower_bound and upper_bound as for floats.
-
-DEFINE_enum: takes a list of strings which represents legal values.  If
-             the command-line value is not in this list, raise a flag
-             error.  Otherwise, assign to FLAGS.flag as a string.
-
-DEFINE_list: Takes a comma-separated list of strings on the commandline.
-             Stores them in a python list object.
-
-DEFINE_spaceseplist: Takes a space-separated list of strings on the
-                     commandline.  Stores them in a python list object.
-                     Example: --myspacesepflag "foo bar baz"
-
-DEFINE_multistring: The same as DEFINE_string, except the flag can be
-                    specified more than once on the commandline.  The
-                    result is a python list object (list of strings),
-                    even if the flag is only on the command line once.
-
-DEFINE_multi_int: The same as DEFINE_integer, except the flag can be
-                  specified more than once on the commandline.  The
-                  result is a python list object (list of ints), even if
-                  the flag is only on the command line once.
-
-
-SPECIAL FLAGS: There are a few flags that have special meaning:
-   --help          prints a list of all the flags in a human-readable fashion
-   --helpshort     prints a list of all key flags (see below).
-   --helpxml       prints a list of all flags, in XML format.  DO NOT parse
-                   the output of --help and --helpshort.  Instead, parse
-                   the output of --helpxml.  For more info, see
-                   "OUTPUT FOR --helpxml" below.
-   --flagfile=foo  read flags from file foo.
-   --undefok=f1,f2 ignore unrecognized option errors for f1,f2.
-                   For boolean flags, you should use --undefok=boolflag, and
-                   --boolflag and --noboolflag will be accepted.  Do not use
-                   --undefok=noboolflag.
-   --              as in getopt(), terminates flag-processing
-
-
-FLAGS VALIDATORS: If your program:
-  - requires flag X to be specified
-  - needs flag Y to match a regular expression
-  - or requires any more general constraint to be satisfied
-then validators are for you!
-
-Each validator represents a constraint over one flag, which is enforced
-starting from the initial parsing of the flags and until the program
-terminates.
-
-Also, lower_bound and upper_bound for numerical flags are enforced using flag
-validators.
-
-Howto:
-If you want to enforce a constraint over one flag, use
-
-gflags.RegisterValidator(flag_name,
-                        checker,
-                        message='Flag validation failed',
-                        flag_values=FLAGS)
-
-After flag values are initially parsed, and after any change to the specified
-flag, method checker(flag_value) will be executed. If constraint is not
-satisfied, an IllegalFlagValue exception will be raised. See
-RegisterValidator's docstring for a detailed explanation on how to construct
-your own checker.
-
-
-EXAMPLE USAGE:
-
-FLAGS = gflags.FLAGS
-
-gflags.DEFINE_integer('my_version', 0, 'Version number.')
-gflags.DEFINE_string('filename', None, 'Input file name', short_name='f')
-
-gflags.RegisterValidator('my_version',
-                        lambda value: value % 2 == 0,
-                        message='--my_version must be divisible by 2')
-gflags.MarkFlagAsRequired('filename')
-
-
-NOTE ON --flagfile:
-
-Flags may be loaded from text files in addition to being specified on
-the commandline.
-
-Any flags you don't feel like typing, throw them in a file, one flag per
-line, for instance:
-   --myflag=myvalue
-   --nomyboolean_flag
-You then specify your file with the special flag '--flagfile=somefile'.
-You CAN recursively nest flagfile= tokens OR use multiple files on the
-command line.  Lines beginning with a single hash '#' or a double slash
-'//' are comments in your flagfile.
-
-Any flagfile=<file> will be interpreted as having a relative path from
-the current working directory rather than from the place the file was
-included from:
-   myPythonScript.py --flagfile=config/somefile.cfg
-
-If somefile.cfg includes further --flagfile= directives, these will be
-referenced relative to the original CWD, not from the directory the
-including flagfile was found in!
-
-The caveat applies to people who are including a series of nested files
-in a different dir than they are executing out of.  Relative path names
-are always from CWD, not from the directory of the parent include
-flagfile. We do now support '~' expanded directory names.
-
-Absolute path names ALWAYS work!
-
-
-EXAMPLE USAGE:
-
-
-  FLAGS = gflags.FLAGS
-
-  # Flag names are globally defined!  So in general, we need to be
-  # careful to pick names that are unlikely to be used by other libraries.
-  # If there is a conflict, we'll get an error at import time.
-  gflags.DEFINE_string('name', 'Mr. President', 'your name')
-  gflags.DEFINE_integer('age', None, 'your age in years', lower_bound=0)
-  gflags.DEFINE_boolean('debug', False, 'produces debugging output')
-  gflags.DEFINE_enum('gender', 'male', ['male', 'female'], 'your gender')
-
-  def main(argv):
-    try:
-      argv = FLAGS(argv)  # parse flags
-    except gflags.FlagsError, e:
-      print '%s\\nUsage: %s ARGS\\n%s' % (e, sys.argv[0], FLAGS)
-      sys.exit(1)
-    if FLAGS.debug: print 'non-flag arguments:', argv
-    print 'Happy Birthday', FLAGS.name
-    if FLAGS.age is not None:
-      print 'You are a %d year old %s' % (FLAGS.age, FLAGS.gender)
-
-  if __name__ == '__main__':
-    main(sys.argv)
-
-
-KEY FLAGS:
-
-As we already explained, each module gains access to all flags defined
-by all the other modules it transitively imports.  In the case of
-non-trivial scripts, this means a lot of flags ...  For documentation
-purposes, it is good to identify the flags that are key (i.e., really
-important) to a module.  Clearly, the concept of "key flag" is a
-subjective one.  When trying to determine whether a flag is key to a
-module or not, assume that you are trying to explain your module to a
-potential user: which flags would you really like to mention first?
-
-We'll describe shortly how to declare which flags are key to a module.
-For the moment, assume we know the set of key flags for each module.
-Then, if you use the app.py module, you can use the --helpshort flag to
-print only the help for the flags that are key to the main module, in a
-human-readable format.
-
-NOTE: If you need to parse the flag help, do NOT use the output of
---help / --helpshort.  That output is meant for human consumption, and
-may be changed in the future.  Instead, use --helpxml; flags that are
-key for the main module are marked there with a <key>yes</key> element.
-
-The set of key flags for a module M is composed of:
-
-1. Flags defined by module M by calling a DEFINE_* function.
-
-2. Flags that module M explictly declares as key by using the function
-
-     DECLARE_key_flag(<flag_name>)
-
-3. Key flags of other modules that M specifies by using the function
-
-     ADOPT_module_key_flags(<other_module>)
-
-   This is a "bulk" declaration of key flags: each flag that is key for
-   <other_module> becomes key for the current module too.
-
-Notice that if you do not use the functions described at points 2 and 3
-above, then --helpshort prints information only about the flags defined
-by the main module of our script.  In many cases, this behavior is good
-enough.  But if you move part of the main module code (together with the
-related flags) into a different module, then it is nice to use
-DECLARE_key_flag / ADOPT_module_key_flags and make sure --helpshort
-lists all relevant flags (otherwise, your code refactoring may confuse
-your users).
-
-Note: each of DECLARE_key_flag / ADOPT_module_key_flags has its own
-pluses and minuses: DECLARE_key_flag is more targeted and may lead a
-more focused --helpshort documentation.  ADOPT_module_key_flags is good
-for cases when an entire module is considered key to the current script.
-Also, it does not require updates to client scripts when a new flag is
-added to the module.
-
-
-EXAMPLE USAGE 2 (WITH KEY FLAGS):
-
-Consider an application that contains the following three files (two
-auxiliary modules and a main module)
-
-File libfoo.py:
-
-  import gflags
-
-  gflags.DEFINE_integer('num_replicas', 3, 'Number of replicas to start')
-  gflags.DEFINE_boolean('rpc2', True, 'Turn on the usage of RPC2.')
-
-  ... some code ...
-
-File libbar.py:
-
-  import gflags
-
-  gflags.DEFINE_string('bar_gfs_path', '/gfs/path',
-                      'Path to the GFS files for libbar.')
-  gflags.DEFINE_string('email_for_bar_errors', 'bar-team@google.com',
-                      'Email address for bug reports about module libbar.')
-  gflags.DEFINE_boolean('bar_risky_hack', False,
-                       'Turn on an experimental and buggy optimization.')
-
-  ... some code ...
-
-File myscript.py:
-
-  import gflags
-  import libfoo
-  import libbar
-
-  gflags.DEFINE_integer('num_iterations', 0, 'Number of iterations.')
-
-  # Declare that all flags that are key for libfoo are
-  # key for this module too.
-  gflags.ADOPT_module_key_flags(libfoo)
-
-  # Declare that the flag --bar_gfs_path (defined in libbar) is key
-  # for this module.
-  gflags.DECLARE_key_flag('bar_gfs_path')
-
-  ... some code ...
-
-When myscript is invoked with the flag --helpshort, the resulted help
-message lists information about all the key flags for myscript:
---num_iterations, --num_replicas, --rpc2, and --bar_gfs_path.
-
-Of course, myscript uses all the flags declared by it (in this case,
-just --num_replicas) or by any of the modules it transitively imports
-(e.g., the modules libfoo, libbar).  E.g., it can access the value of
-FLAGS.bar_risky_hack, even if --bar_risky_hack is not declared as a key
-flag for myscript.
-
-
-OUTPUT FOR --helpxml:
-
-The --helpxml flag generates output with the following structure:
-
-<?xml version="1.0"?>
-<AllFlags>
-  <program>PROGRAM_BASENAME</program>
-  <usage>MAIN_MODULE_DOCSTRING</usage>
-  (<flag>
-    [<key>yes</key>]
-    <file>DECLARING_MODULE</file>
-    <name>FLAG_NAME</name>
-    <meaning>FLAG_HELP_MESSAGE</meaning>
-    <default>DEFAULT_FLAG_VALUE</default>
-    <current>CURRENT_FLAG_VALUE</current>
-    <type>FLAG_TYPE</type>
-    [OPTIONAL_ELEMENTS]
-  </flag>)*
-</AllFlags>
-
-Notes:
-
-1. The output is intentionally similar to the output generated by the
-C++ command-line flag library.  The few differences are due to the
-Python flags that do not have a C++ equivalent (at least not yet),
-e.g., DEFINE_list.
-
-2. New XML elements may be added in the future.
-
-3. DEFAULT_FLAG_VALUE is in serialized form, i.e., the string you can
-pass for this flag on the command-line.  E.g., for a flag defined
-using DEFINE_list, this field may be foo,bar, not ['foo', 'bar'].
-
-4. CURRENT_FLAG_VALUE is produced using str().  This means that the
-string 'false' will be represented in the same way as the boolean
-False.  Using repr() would have removed this ambiguity and simplified
-parsing, but would have broken the compatibility with the C++
-command-line flags.
-
-5. OPTIONAL_ELEMENTS describe elements relevant for certain kinds of
-flags: lower_bound, upper_bound (for flags that specify bounds),
-enum_value (for enum flags), list_separator (for flags that consist of
-a list of values, separated by a special token).
-
-6. We do not provide any example here: please use --helpxml instead.
-
-This module requires at least python 2.2.1 to run.
-"""
-
-import cgi
-import getopt
-import os
-import re
-import string
-import struct
-import sys
-# pylint: disable-msg=C6204
-try:
-  import fcntl
-except ImportError:
-  fcntl = None
-try:
-  # Importing termios will fail on non-unix platforms.
-  import termios
-except ImportError:
-  termios = None
-
-import gflags_validators
-# pylint: enable-msg=C6204
-
-
-# Are we running under pychecker?
-_RUNNING_PYCHECKER = 'pychecker.python' in sys.modules
-
-
-def _GetCallingModuleObjectAndName():
-  """Returns the module that's calling into this module.
-
-  We generally use this function to get the name of the module calling a
-  DEFINE_foo... function.
-  """
-  # Walk down the stack to find the first globals dict that's not ours.
-  for depth in range(1, sys.getrecursionlimit()):
-    if not sys._getframe(depth).f_globals is globals():
-      globals_for_frame = sys._getframe(depth).f_globals
-      module, module_name = _GetModuleObjectAndName(globals_for_frame)
-      if module_name is not None:
-        return module, module_name
-  raise AssertionError("No module was found")
-
-
-def _GetCallingModule():
-  """Returns the name of the module that's calling into this module."""
-  return _GetCallingModuleObjectAndName()[1]
-
-
-def _GetThisModuleObjectAndName():
-  """Returns: (module object, module name) for this module."""
-  return _GetModuleObjectAndName(globals())
-
-
-# module exceptions:
-class FlagsError(Exception):
-  """The base class for all flags errors."""
-  pass
-
-
-class DuplicateFlag(FlagsError):
-  """Raised if there is a flag naming conflict."""
-  pass
-
-class CantOpenFlagFileError(FlagsError):
-  """Raised if flagfile fails to open: doesn't exist, wrong permissions, etc."""
-  pass
-
-
-class DuplicateFlagCannotPropagateNoneToSwig(DuplicateFlag):
-  """Special case of DuplicateFlag -- SWIG flag value can't be set to None.
-
-  This can be raised when a duplicate flag is created. Even if allow_override is
-  True, we still abort if the new value is None, because it's currently
-  impossible to pass None default value back to SWIG. See FlagValues.SetDefault
-  for details.
-  """
-  pass
-
-
-class DuplicateFlagError(DuplicateFlag):
-  """A DuplicateFlag whose message cites the conflicting definitions.
-
-  A DuplicateFlagError conveys more information than a DuplicateFlag,
-  namely the modules where the conflicting definitions occur. This
-  class was created to avoid breaking external modules which depend on
-  the existing DuplicateFlags interface.
-  """
-
-  def __init__(self, flagname, flag_values, other_flag_values=None):
-    """Create a DuplicateFlagError.
-
-    Args:
-      flagname: Name of the flag being redefined.
-      flag_values: FlagValues object containing the first definition of
-          flagname.
-      other_flag_values: If this argument is not None, it should be the
-          FlagValues object where the second definition of flagname occurs.
-          If it is None, we assume that we're being called when attempting
-          to create the flag a second time, and we use the module calling
-          this one as the source of the second definition.
-    """
-    self.flagname = flagname
-    first_module = flag_values.FindModuleDefiningFlag(
-        flagname, default='<unknown>')
-    if other_flag_values is None:
-      second_module = _GetCallingModule()
-    else:
-      second_module = other_flag_values.FindModuleDefiningFlag(
-          flagname, default='<unknown>')
-    msg = "The flag '%s' is defined twice. First from %s, Second from %s" % (
-        self.flagname, first_module, second_module)
-    DuplicateFlag.__init__(self, msg)
-
-
-class IllegalFlagValue(FlagsError):
-  """The flag command line argument is illegal."""
-  pass
-
-
-class UnrecognizedFlag(FlagsError):
-  """Raised if a flag is unrecognized."""
-  pass
-
-
-# An UnrecognizedFlagError conveys more information than an UnrecognizedFlag.
-# Since there are external modules that create DuplicateFlags, the interface to
-# DuplicateFlag shouldn't change.  The flagvalue will be assigned the full value
-# of the flag and its argument, if any, allowing handling of unrecognized flags
-# in an exception handler.
-# If flagvalue is the empty string, then this exception is an due to a
-# reference to a flag that was not already defined.
-class UnrecognizedFlagError(UnrecognizedFlag):
-  def __init__(self, flagname, flagvalue=''):
-    self.flagname = flagname
-    self.flagvalue = flagvalue
-    UnrecognizedFlag.__init__(
-        self, "Unknown command line flag '%s'" % flagname)
-
-# Global variable used by expvar
-_exported_flags = {}
-_help_width = 80  # width of help output
-
-
-def GetHelpWidth():
-  """Returns: an integer, the width of help lines that is used in TextWrap."""
-  if (not sys.stdout.isatty()) or (termios is None) or (fcntl is None):
-    return _help_width
-  try:
-    data = fcntl.ioctl(sys.stdout, termios.TIOCGWINSZ, '1234')
-    columns = struct.unpack('hh', data)[1]
-    # Emacs mode returns 0.
-    # Here we assume that any value below 40 is unreasonable
-    if columns >= 40:
-      return columns
-    # Returning an int as default is fine, int(int) just return the int.
-    return int(os.getenv('COLUMNS', _help_width))
-
-  except (TypeError, IOError, struct.error):
-    return _help_width
-
-
-def CutCommonSpacePrefix(text):
-  """Removes a common space prefix from the lines of a multiline text.
-
-  If the first line does not start with a space, it is left as it is and
-  only in the remaining lines a common space prefix is being searched
-  for. That means the first line will stay untouched. This is especially
-  useful to turn doc strings into help texts. This is because some
-  people prefer to have the doc comment start already after the
-  apostrophe and then align the following lines while others have the
-  apostrophes on a separate line.
-
-  The function also drops trailing empty lines and ignores empty lines
-  following the initial content line while calculating the initial
-  common whitespace.
-
-  Args:
-    text: text to work on
-
-  Returns:
-    the resulting text
-  """
-  text_lines = text.splitlines()
-  # Drop trailing empty lines
-  while text_lines and not text_lines[-1]:
-    text_lines = text_lines[:-1]
-  if text_lines:
-    # We got some content, is the first line starting with a space?
-    if text_lines[0] and text_lines[0][0].isspace():
-      text_first_line = []
-    else:
-      text_first_line = [text_lines.pop(0)]
-    # Calculate length of common leading whitespace (only over content lines)
-    common_prefix = os.path.commonprefix([line for line in text_lines if line])
-    space_prefix_len = len(common_prefix) - len(common_prefix.lstrip())
-    # If we have a common space prefix, drop it from all lines
-    if space_prefix_len:
-      for index in xrange(len(text_lines)):
-        if text_lines[index]:
-          text_lines[index] = text_lines[index][space_prefix_len:]
-    return '\n'.join(text_first_line + text_lines)
-  return ''
-
-
-def TextWrap(text, length=None, indent='', firstline_indent=None, tabs='    '):
-  """Wraps a given text to a maximum line length and returns it.
-
-  We turn lines that only contain whitespace into empty lines.  We keep
-  new lines and tabs (e.g., we do not treat tabs as spaces).
-
-  Args:
-    text:             text to wrap
-    length:           maximum length of a line, includes indentation
-                      if this is None then use GetHelpWidth()
-    indent:           indent for all but first line
-    firstline_indent: indent for first line; if None, fall back to indent
-    tabs:             replacement for tabs
-
-  Returns:
-    wrapped text
-
-  Raises:
-    FlagsError: if indent not shorter than length
-    FlagsError: if firstline_indent not shorter than length
-  """
-  # Get defaults where callee used None
-  if length is None:
-    length = GetHelpWidth()
-  if indent is None:
-    indent = ''
-  if len(indent) >= length:
-    raise FlagsError('Indent must be shorter than length')
-  # In line we will be holding the current line which is to be started
-  # with indent (or firstline_indent if available) and then appended
-  # with words.
-  if firstline_indent is None:
-    firstline_indent = ''
-    line = indent
-  else:
-    line = firstline_indent
-    if len(firstline_indent) >= length:
-      raise FlagsError('First line indent must be shorter than length')
-
-  # If the callee does not care about tabs we simply convert them to
-  # spaces If callee wanted tabs to be single space then we do that
-  # already here.
-  if not tabs or tabs == ' ':
-    text = text.replace('\t', ' ')
-  else:
-    tabs_are_whitespace = not tabs.strip()
-
-  line_regex = re.compile('([ ]*)(\t*)([^ \t]+)', re.MULTILINE)
-
-  # Split the text into lines and the lines with the regex above. The
-  # resulting lines are collected in result[]. For each split we get the
-  # spaces, the tabs and the next non white space (e.g. next word).
-  result = []
-  for text_line in text.splitlines():
-    # Store result length so we can find out whether processing the next
-    # line gave any new content
-    old_result_len = len(result)
-    # Process next line with line_regex. For optimization we do an rstrip().
-    # - process tabs (changes either line or word, see below)
-    # - process word (first try to squeeze on line, then wrap or force wrap)
-    # Spaces found on the line are ignored, they get added while wrapping as
-    # needed.
-    for spaces, current_tabs, word in line_regex.findall(text_line.rstrip()):
-      # If tabs weren't converted to spaces, handle them now
-      if current_tabs:
-        # If the last thing we added was a space anyway then drop
-        # it. But let's not get rid of the indentation.
-        if (((result and line != indent) or
-             (not result and line != firstline_indent)) and line[-1] == ' '):
-          line = line[:-1]
-        # Add the tabs, if that means adding whitespace, just add it at
-        # the line, the rstrip() code while shorten the line down if
-        # necessary
-        if tabs_are_whitespace:
-          line += tabs * len(current_tabs)
-        else:
-          # if not all tab replacement is whitespace we prepend it to the word
-          word = tabs * len(current_tabs) + word
-      # Handle the case where word cannot be squeezed onto current last line
-      if len(line) + len(word) > length and len(indent) + len(word) <= length:
-        result.append(line.rstrip())
-        line = indent + word
-        word = ''
-        # No space left on line or can we append a space?
-        if len(line) + 1 >= length:
-          result.append(line.rstrip())
-          line = indent
-        else:
-          line += ' '
-      # Add word and shorten it up to allowed line length. Restart next
-      # line with indent and repeat, or add a space if we're done (word
-      # finished) This deals with words that cannot fit on one line
-      # (e.g. indent + word longer than allowed line length).
-      while len(line) + len(word) >= length:
-        line += word
-        result.append(line[:length])
-        word = line[length:]
-        line = indent
-      # Default case, simply append the word and a space
-      if word:
-        line += word + ' '
-    # End of input line. If we have content we finish the line. If the
-    # current line is just the indent but we had content in during this
-    # original line then we need to add an empty line.
-    if (result and line != indent) or (not result and line != firstline_indent):
-      result.append(line.rstrip())
-    elif len(result) == old_result_len:
-      result.append('')
-    line = indent
-
-  return '\n'.join(result)
-
-
-def DocToHelp(doc):
-  """Takes a __doc__ string and reformats it as help."""
-
-  # Get rid of starting and ending white space. Using lstrip() or even
-  # strip() could drop more than maximum of first line and right space
-  # of last line.
-  doc = doc.strip()
-
-  # Get rid of all empty lines
-  whitespace_only_line = re.compile('^[ \t]+$', re.M)
-  doc = whitespace_only_line.sub('', doc)
-
-  # Cut out common space at line beginnings
-  doc = CutCommonSpacePrefix(doc)
-
-  # Just like this module's comment, comments tend to be aligned somehow.
-  # In other words they all start with the same amount of white space
-  # 1) keep double new lines
-  # 2) keep ws after new lines if not empty line
-  # 3) all other new lines shall be changed to a space
-  # Solution: Match new lines between non white space and replace with space.
-  doc = re.sub('(?<=\S)\n(?=\S)', ' ', doc, re.M)
-
-  return doc
-
-
-def _GetModuleObjectAndName(globals_dict):
-  """Returns the module that defines a global environment, and its name.
-
-  Args:
-    globals_dict: A dictionary that should correspond to an environment
-      providing the values of the globals.
-
-  Returns:
-    A pair consisting of (1) module object and (2) module name (a
-    string).  Returns (None, None) if the module could not be
-    identified.
-  """
-  # The use of .items() (instead of .iteritems()) is NOT a mistake: if
-  # a parallel thread imports a module while we iterate over
-  # .iteritems() (not nice, but possible), we get a RuntimeError ...
-  # Hence, we use the slightly slower but safer .items().
-  for name, module in sys.modules.items():
-    if getattr(module, '__dict__', None) is globals_dict:
-      if name == '__main__':
-        # Pick a more informative name for the main module.
-        name = sys.argv[0]
-      return (module, name)
-  return (None, None)
-
-
-def _GetMainModule():
-  """Returns: string, name of the module from which execution started."""
-  # First, try to use the same logic used by _GetCallingModuleObjectAndName(),
-  # i.e., call _GetModuleObjectAndName().  For that we first need to
-  # find the dictionary that the main module uses to store the
-  # globals.
-  #
-  # That's (normally) the same dictionary object that the deepest
-  # (oldest) stack frame is using for globals.
-  deepest_frame = sys._getframe(0)
-  while deepest_frame.f_back is not None:
-    deepest_frame = deepest_frame.f_back
-  globals_for_main_module = deepest_frame.f_globals
-  main_module_name = _GetModuleObjectAndName(globals_for_main_module)[1]
-  # The above strategy fails in some cases (e.g., tools that compute
-  # code coverage by redefining, among other things, the main module).
-  # If so, just use sys.argv[0].  We can probably always do this, but
-  # it's safest to try to use the same logic as _GetCallingModuleObjectAndName()
-  if main_module_name is None:
-    main_module_name = sys.argv[0]
-  return main_module_name
-
-
-class FlagValues:
-  """Registry of 'Flag' objects.
-
-  A 'FlagValues' can then scan command line arguments, passing flag
-  arguments through to the 'Flag' objects that it owns.  It also
-  provides easy access to the flag values.  Typically only one
-  'FlagValues' object is needed by an application: gflags.FLAGS
-
-  This class is heavily overloaded:
-
-  'Flag' objects are registered via __setitem__:
-       FLAGS['longname'] = x   # register a new flag
-
-  The .value attribute of the registered 'Flag' objects can be accessed
-  as attributes of this 'FlagValues' object, through __getattr__.  Both
-  the long and short name of the original 'Flag' objects can be used to
-  access its value:
-       FLAGS.longname          # parsed flag value
-       FLAGS.x                 # parsed flag value (short name)
-
-  Command line arguments are scanned and passed to the registered 'Flag'
-  objects through the __call__ method.  Unparsed arguments, including
-  argv[0] (e.g. the program name) are returned.
-       argv = FLAGS(sys.argv)  # scan command line arguments
-
-  The original registered Flag objects can be retrieved through the use
-  of the dictionary-like operator, __getitem__:
-       x = FLAGS['longname']   # access the registered Flag object
-
-  The str() operator of a 'FlagValues' object provides help for all of
-  the registered 'Flag' objects.
-  """
-
-  def __init__(self):
-    # Since everything in this class is so heavily overloaded, the only
-    # way of defining and using fields is to access __dict__ directly.
-
-    # Dictionary: flag name (string) -> Flag object.
-    self.__dict__['__flags'] = {}
-    # Dictionary: module name (string) -> list of Flag objects that are defined
-    # by that module.
-    self.__dict__['__flags_by_module'] = {}
-    # Dictionary: module id (int) -> list of Flag objects that are defined by
-    # that module.
-    self.__dict__['__flags_by_module_id'] = {}
-    # Dictionary: module name (string) -> list of Flag objects that are
-    # key for that module.
-    self.__dict__['__key_flags_by_module'] = {}
-
-    # Set if we should use new style gnu_getopt rather than getopt when parsing
-    # the args.  Only possible with Python 2.3+
-    self.UseGnuGetOpt(False)
-
-  def UseGnuGetOpt(self, use_gnu_getopt=True):
-    """Use GNU-style scanning. Allows mixing of flag and non-flag arguments.
-
-    See http://docs.python.org/library/getopt.html#getopt.gnu_getopt
-
-    Args:
-      use_gnu_getopt: wether or not to use GNU style scanning.
-    """
-    self.__dict__['__use_gnu_getopt'] = use_gnu_getopt
-
-  def IsGnuGetOpt(self):
-    return self.__dict__['__use_gnu_getopt']
-
-  def FlagDict(self):
-    return self.__dict__['__flags']
-
-  def FlagsByModuleDict(self):
-    """Returns the dictionary of module_name -> list of defined flags.
-
-    Returns:
-      A dictionary.  Its keys are module names (strings).  Its values
-      are lists of Flag objects.
-    """
-    return self.__dict__['__flags_by_module']
-
-  def FlagsByModuleIdDict(self):
-    """Returns the dictionary of module_id -> list of defined flags.
-
-    Returns:
-      A dictionary.  Its keys are module IDs (ints).  Its values
-      are lists of Flag objects.
-    """
-    return self.__dict__['__flags_by_module_id']
-
-  def KeyFlagsByModuleDict(self):
-    """Returns the dictionary of module_name -> list of key flags.
-
-    Returns:
-      A dictionary.  Its keys are module names (strings).  Its values
-      are lists of Flag objects.
-    """
-    return self.__dict__['__key_flags_by_module']
-
-  def _RegisterFlagByModule(self, module_name, flag):
-    """Records the module that defines a specific flag.
-
-    We keep track of which flag is defined by which module so that we
-    can later sort the flags by module.
-
-    Args:
-      module_name: A string, the name of a Python module.
-      flag: A Flag object, a flag that is key to the module.
-    """
-    flags_by_module = self.FlagsByModuleDict()
-    flags_by_module.setdefault(module_name, []).append(flag)
-
-  def _RegisterFlagByModuleId(self, module_id, flag):
-    """Records the module that defines a specific flag.
-
-    Args:
-      module_id: An int, the ID of the Python module.
-      flag: A Flag object, a flag that is key to the module.
-    """
-    flags_by_module_id = self.FlagsByModuleIdDict()
-    flags_by_module_id.setdefault(module_id, []).append(flag)
-
-  def _RegisterKeyFlagForModule(self, module_name, flag):
-    """Specifies that a flag is a key flag for a module.
-
-    Args:
-      module_name: A string, the name of a Python module.
-      flag: A Flag object, a flag that is key to the module.
-    """
-    key_flags_by_module = self.KeyFlagsByModuleDict()
-    # The list of key flags for the module named module_name.
-    key_flags = key_flags_by_module.setdefault(module_name, [])
-    # Add flag, but avoid duplicates.
-    if flag not in key_flags:
-      key_flags.append(flag)
-
-  def _GetFlagsDefinedByModule(self, module):
-    """Returns the list of flags defined by a module.
-
-    Args:
-      module: A module object or a module name (a string).
-
-    Returns:
-      A new list of Flag objects.  Caller may update this list as he
-      wishes: none of those changes will affect the internals of this
-      FlagValue object.
-    """
-    if not isinstance(module, str):
-      module = module.__name__
-
-    return list(self.FlagsByModuleDict().get(module, []))
-
-  def _GetKeyFlagsForModule(self, module):
-    """Returns the list of key flags for a module.
-
-    Args:
-      module: A module object or a module name (a string)
-
-    Returns:
-      A new list of Flag objects.  Caller may update this list as he
-      wishes: none of those changes will affect the internals of this
-      FlagValue object.
-    """
-    if not isinstance(module, str):
-      module = module.__name__
-
-    # Any flag is a key flag for the module that defined it.  NOTE:
-    # key_flags is a fresh list: we can update it without affecting the
-    # internals of this FlagValues object.
-    key_flags = self._GetFlagsDefinedByModule(module)
-
-    # Take into account flags explicitly declared as key for a module.
-    for flag in self.KeyFlagsByModuleDict().get(module, []):
-      if flag not in key_flags:
-        key_flags.append(flag)
-    return key_flags
-
-  def FindModuleDefiningFlag(self, flagname, default=None):
-    """Return the name of the module defining this flag, or default.
-
-    Args:
-      flagname: Name of the flag to lookup.
-      default: Value to return if flagname is not defined. Defaults
-          to None.
-
-    Returns:
-      The name of the module which registered the flag with this name.
-      If no such module exists (i.e. no flag with this name exists),
-      we return default.
-    """
-    for module, flags in self.FlagsByModuleDict().iteritems():
-      for flag in flags:
-        if flag.name == flagname or flag.short_name == flagname:
-          return module
-    return default
-
-  def FindModuleIdDefiningFlag(self, flagname, default=None):
-    """Return the ID of the module defining this flag, or default.
-
-    Args:
-      flagname: Name of the flag to lookup.
-      default: Value to return if flagname is not defined. Defaults
-          to None.
-
-    Returns:
-      The ID of the module which registered the flag with this name.
-      If no such module exists (i.e. no flag with this name exists),
-      we return default.
-    """
-    for module_id, flags in self.FlagsByModuleIdDict().iteritems():
-      for flag in flags:
-        if flag.name == flagname or flag.short_name == flagname:
-          return module_id
-    return default
-
-  def AppendFlagValues(self, flag_values):
-    """Appends flags registered in another FlagValues instance.
-
-    Args:
-      flag_values: registry to copy from
-    """
-    for flag_name, flag in flag_values.FlagDict().iteritems():
-      # Each flags with shortname appears here twice (once under its
-      # normal name, and again with its short name).  To prevent
-      # problems (DuplicateFlagError) with double flag registration, we
-      # perform a check to make sure that the entry we're looking at is
-      # for its normal name.
-      if flag_name == flag.name:
-        try:
-          self[flag_name] = flag
-        except DuplicateFlagError:
-          raise DuplicateFlagError(flag_name, self,
-                                   other_flag_values=flag_values)
-
-  def RemoveFlagValues(self, flag_values):
-    """Remove flags that were previously appended from another FlagValues.
-
-    Args:
-      flag_values: registry containing flags to remove.
-    """
-    for flag_name in flag_values.FlagDict():
-      self.__delattr__(flag_name)
-
-  def __setitem__(self, name, flag):
-    """Registers a new flag variable."""
-    fl = self.FlagDict()
-    if not isinstance(flag, Flag):
-      raise IllegalFlagValue(flag)
-    if not isinstance(name, type("")):
-      raise FlagsError("Flag name must be a string")
-    if len(name) == 0:
-      raise FlagsError("Flag name cannot be empty")
-    # If running under pychecker, duplicate keys are likely to be
-    # defined.  Disable check for duplicate keys when pycheck'ing.
-    if (name in fl and not flag.allow_override and
-        not fl[name].allow_override and not _RUNNING_PYCHECKER):
-      module, module_name = _GetCallingModuleObjectAndName()
-      if (self.FindModuleDefiningFlag(name) == module_name and
-          id(module) != self.FindModuleIdDefiningFlag(name)):
-        # If the flag has already been defined by a module with the same name,
-        # but a different ID, we can stop here because it indicates that the
-        # module is simply being imported a subsequent time.
-        return
-      raise DuplicateFlagError(name, self)
-    short_name = flag.short_name
-    if short_name is not None:
-      if (short_name in fl and not flag.allow_override and
-          not fl[short_name].allow_override and not _RUNNING_PYCHECKER):
-        raise DuplicateFlagError(short_name, self)
-      fl[short_name] = flag
-    fl[name] = flag
-    global _exported_flags
-    _exported_flags[name] = flag
-
-  def __getitem__(self, name):
-    """Retrieves the Flag object for the flag --name."""
-    return self.FlagDict()[name]
-
-  def __getattr__(self, name):
-    """Retrieves the 'value' attribute of the flag --name."""
-    fl = self.FlagDict()
-    if name not in fl:
-      raise AttributeError(name)
-    return fl[name].value
-
-  def __setattr__(self, name, value):
-    """Sets the 'value' attribute of the flag --name."""
-    fl = self.FlagDict()
-    fl[name].value = value
-    self._AssertValidators(fl[name].validators)
-    return value
-
-  def _AssertAllValidators(self):
-    all_validators = set()
-    for flag in self.FlagDict().itervalues():
-      for validator in flag.validators:
-        all_validators.add(validator)
-    self._AssertValidators(all_validators)
-
-  def _AssertValidators(self, validators):
-    """Assert if all validators in the list are satisfied.
-
-    Asserts validators in the order they were created.
-    Args:
-      validators: Iterable(gflags_validators.Validator), validators to be
-        verified
-    Raises:
-      AttributeError: if validators work with a non-existing flag.
-      IllegalFlagValue: if validation fails for at least one validator
-    """
-    for validator in sorted(
-        validators, key=lambda validator: validator.insertion_index):
-      try:
-        validator.Verify(self)
-      except gflags_validators.Error, e:
-        message = validator.PrintFlagsWithValues(self)
-        raise IllegalFlagValue('%s: %s' % (message, str(e)))
-
-  def _FlagIsRegistered(self, flag_obj):
-    """Checks whether a Flag object is registered under some name.
-
-    Note: this is non trivial: in addition to its normal name, a flag
-    may have a short name too.  In self.FlagDict(), both the normal and
-    the short name are mapped to the same flag object.  E.g., calling
-    only "del FLAGS.short_name" is not unregistering the corresponding
-    Flag object (it is still registered under the longer name).
-
-    Args:
-      flag_obj: A Flag object.
-
-    Returns:
-      A boolean: True iff flag_obj is registered under some name.
-    """
-    flag_dict = self.FlagDict()
-    # Check whether flag_obj is registered under its long name.
-    name = flag_obj.name
-    if flag_dict.get(name, None) == flag_obj:
-      return True
-    # Check whether flag_obj is registered under its short name.
-    short_name = flag_obj.short_name
-    if (short_name is not None and
-        flag_dict.get(short_name, None) == flag_obj):
-      return True
-    # The flag cannot be registered under any other name, so we do not
-    # need to do a full search through the values of self.FlagDict().
-    return False
-
-  def __delattr__(self, flag_name):
-    """Deletes a previously-defined flag from a flag object.
-
-    This method makes sure we can delete a flag by using
-
-      del flag_values_object.<flag_name>
-
-    E.g.,
-
-      gflags.DEFINE_integer('foo', 1, 'Integer flag.')
-      del gflags.FLAGS.foo
-
-    Args:
-      flag_name: A string, the name of the flag to be deleted.
-
-    Raises:
-      AttributeError: When there is no registered flag named flag_name.
-    """
-    fl = self.FlagDict()
-    if flag_name not in fl:
-      raise AttributeError(flag_name)
-
-    flag_obj = fl[flag_name]
-    del fl[flag_name]
-
-    if not self._FlagIsRegistered(flag_obj):
-      # If the Flag object indicated by flag_name is no longer
-      # registered (please see the docstring of _FlagIsRegistered), then
-      # we delete the occurrences of the flag object in all our internal
-      # dictionaries.
-      self.__RemoveFlagFromDictByModule(self.FlagsByModuleDict(), flag_obj)
-      self.__RemoveFlagFromDictByModule(self.FlagsByModuleIdDict(), flag_obj)
-      self.__RemoveFlagFromDictByModule(self.KeyFlagsByModuleDict(), flag_obj)
-
-  def __RemoveFlagFromDictByModule(self, flags_by_module_dict, flag_obj):
-    """Removes a flag object from a module -> list of flags dictionary.
-
-    Args:
-      flags_by_module_dict: A dictionary that maps module names to lists of
-        flags.
-      flag_obj: A flag object.
-    """
-    for unused_module, flags_in_module in flags_by_module_dict.iteritems():
-      # while (as opposed to if) takes care of multiple occurrences of a
-      # flag in the list for the same module.
-      while flag_obj in flags_in_module:
-        flags_in_module.remove(flag_obj)
-
-  def SetDefault(self, name, value):
-    """Changes the default value of the named flag object."""
-    fl = self.FlagDict()
-    if name not in fl:
-      raise AttributeError(name)
-    fl[name].SetDefault(value)
-    self._AssertValidators(fl[name].validators)
-
-  def __contains__(self, name):
-    """Returns True if name is a value (flag) in the dict."""
-    return name in self.FlagDict()
-
-  has_key = __contains__  # a synonym for __contains__()
-
-  def __iter__(self):
-    return iter(self.FlagDict())
-
-  def __call__(self, argv):
-    """Parses flags from argv; stores parsed flags into this FlagValues object.
-
-    All unparsed arguments are returned.  Flags are parsed using the GNU
-    Program Argument Syntax Conventions, using getopt:
-
-    http://www.gnu.org/software/libc/manual/html_mono/libc.html#Getopt
-
-    Args:
-       argv: argument list. Can be of any type that may be converted to a list.
-
-    Returns:
-       The list of arguments not parsed as options, including argv[0]
-
-    Raises:
-       FlagsError: on any parsing error
-    """
-    # Support any sequence type that can be converted to a list
-    argv = list(argv)
-
-    shortopts = ""
-    longopts = []
-
-    fl = self.FlagDict()
-
-    # This pre parses the argv list for --flagfile=<> options.
-    argv = argv[:1] + self.ReadFlagsFromFiles(argv[1:], force_gnu=False)
-
-    # Correct the argv to support the google style of passing boolean
-    # parameters.  Boolean parameters may be passed by using --mybool,
-    # --nomybool, --mybool=(true|false|1|0).  getopt does not support
-    # having options that may or may not have a parameter.  We replace
-    # instances of the short form --mybool and --nomybool with their
-    # full forms: --mybool=(true|false).
-    original_argv = list(argv)  # list() makes a copy
-    shortest_matches = None
-    for name, flag in fl.items():
-      if not flag.boolean:
-        continue
-      if shortest_matches is None:
-        # Determine the smallest allowable prefix for all flag names
-        shortest_matches = self.ShortestUniquePrefixes(fl)
-      no_name = 'no' + name
-      prefix = shortest_matches[name]
-      no_prefix = shortest_matches[no_name]
-
-      # Replace all occurrences of this boolean with extended forms
-      for arg_idx in range(1, len(argv)):
-        arg = argv[arg_idx]
-        if arg.find('=') >= 0: continue
-        if arg.startswith('--'+prefix) and ('--'+name).startswith(arg):
-          argv[arg_idx] = ('--%s=true' % name)
-        elif arg.startswith('--'+no_prefix) and ('--'+no_name).startswith(arg):
-          argv[arg_idx] = ('--%s=false' % name)
-
-    # Loop over all of the flags, building up the lists of short options
-    # and long options that will be passed to getopt.  Short options are
-    # specified as a string of letters, each letter followed by a colon
-    # if it takes an argument.  Long options are stored in an array of
-    # strings.  Each string ends with an '=' if it takes an argument.
-    for name, flag in fl.items():
-      longopts.append(name + "=")
-      if len(name) == 1:  # one-letter option: allow short flag type also
-        shortopts += name
-        if not flag.boolean:
-          shortopts += ":"
-
-    longopts.append('undefok=')
-    undefok_flags = []
-
-    # In case --undefok is specified, loop to pick up unrecognized
-    # options one by one.
-    unrecognized_opts = []
-    args = argv[1:]
-    while True:
-      try:
-        if self.__dict__['__use_gnu_getopt']:
-          optlist, unparsed_args = getopt.gnu_getopt(args, shortopts, longopts)
-        else:
-          optlist, unparsed_args = getopt.getopt(args, shortopts, longopts)
-        break
-      except getopt.GetoptError, e:
-        if not e.opt or e.opt in fl:
-          # Not an unrecognized option, re-raise the exception as a FlagsError
-          raise FlagsError(e)
-        # Remove offender from args and try again
-        for arg_index in range(len(args)):
-          if ((args[arg_index] == '--' + e.opt) or
-              (args[arg_index] == '-' + e.opt) or
-              (args[arg_index].startswith('--' + e.opt + '='))):
-            unrecognized_opts.append((e.opt, args[arg_index]))
-            args = args[0:arg_index] + args[arg_index+1:]
-            break
-        else:
-          # We should have found the option, so we don't expect to get
-          # here.  We could assert, but raising the original exception
-          # might work better.
-          raise FlagsError(e)
-
-    for name, arg in optlist:
-      if name == '--undefok':
-        flag_names = arg.split(',')
-        undefok_flags.extend(flag_names)
-        # For boolean flags, if --undefok=boolflag is specified, then we should
-        # also accept --noboolflag, in addition to --boolflag.
-        # Since we don't know the type of the undefok'd flag, this will affect
-        # non-boolean flags as well.
-        # NOTE: You shouldn't use --undefok=noboolflag, because then we will
-        # accept --nonoboolflag here.  We are choosing not to do the conversion
-        # from noboolflag -> boolflag because of the ambiguity that flag names
-        # can start with 'no'.
-        undefok_flags.extend('no' + name for name in flag_names)
-        continue
-      if name.startswith('--'):
-        # long option
-        name = name[2:]
-        short_option = 0
-      else:
-        # short option
-        name = name[1:]
-        short_option = 1
-      if name in fl:
-        flag = fl[name]
-        if flag.boolean and short_option: arg = 1
-        flag.Parse(arg)
-
-    # If there were unrecognized options, raise an exception unless
-    # the options were named via --undefok.
-    for opt, value in unrecognized_opts:
-      if opt not in undefok_flags:
-        raise UnrecognizedFlagError(opt, value)
-
-    if unparsed_args:
-      if self.__dict__['__use_gnu_getopt']:
-        # if using gnu_getopt just return the program name + remainder of argv.
-        ret_val = argv[:1] + unparsed_args
-      else:
-        # unparsed_args becomes the first non-flag detected by getopt to
-        # the end of argv.  Because argv may have been modified above,
-        # return original_argv for this region.
-        ret_val = argv[:1] + original_argv[-len(unparsed_args):]
-    else:
-      ret_val = argv[:1]
-
-    self._AssertAllValidators()
-    return ret_val
-
-  def Reset(self):
-    """Resets the values to the point before FLAGS(argv) was called."""
-    for f in self.FlagDict().values():
-      f.Unparse()
-
-  def RegisteredFlags(self):
-    """Returns: a list of the names and short names of all registered flags."""
-    return list(self.FlagDict())
-
-  def FlagValuesDict(self):
-    """Returns: a dictionary that maps flag names to flag values."""
-    flag_values = {}
-
-    for flag_name in self.RegisteredFlags():
-      flag = self.FlagDict()[flag_name]
-      flag_values[flag_name] = flag.value
-
-    return flag_values
-
-  def __str__(self):
-    """Generates a help string for all known flags."""
-    return self.GetHelp()
-
-  def GetHelp(self, prefix=''):
-    """Generates a help string for all known flags."""
-    helplist = []
-
-    flags_by_module = self.FlagsByModuleDict()
-    if flags_by_module:
-
-      modules = sorted(flags_by_module)
-
-      # Print the help for the main module first, if possible.
-      main_module = _GetMainModule()
-      if main_module in modules:
-        modules.remove(main_module)
-        modules = [main_module] + modules
-
-      for module in modules:
-        self.__RenderOurModuleFlags(module, helplist)
-
-      self.__RenderModuleFlags('gflags',
-                               _SPECIAL_FLAGS.FlagDict().values(),
-                               helplist)
-
-    else:
-      # Just print one long list of flags.
-      self.__RenderFlagList(
-          self.FlagDict().values() + _SPECIAL_FLAGS.FlagDict().values(),
-          helplist, prefix)
-
-    return '\n'.join(helplist)
-
-  def __RenderModuleFlags(self, module, flags, output_lines, prefix=""):
-    """Generates a help string for a given module."""
-    if not isinstance(module, str):
-      module = module.__name__
-    output_lines.append('\n%s%s:' % (prefix, module))
-    self.__RenderFlagList(flags, output_lines, prefix + "  ")
-
-  def __RenderOurModuleFlags(self, module, output_lines, prefix=""):
-    """Generates a help string for a given module."""
-    flags = self._GetFlagsDefinedByModule(module)
-    if flags:
-      self.__RenderModuleFlags(module, flags, output_lines, prefix)
-
-  def __RenderOurModuleKeyFlags(self, module, output_lines, prefix=""):
-    """Generates a help string for the key flags of a given module.
-
-    Args:
-      module: A module object or a module name (a string).
-      output_lines: A list of strings.  The generated help message
-        lines will be appended to this list.
-      prefix: A string that is prepended to each generated help line.
-    """
-    key_flags = self._GetKeyFlagsForModule(module)
-    if key_flags:
-      self.__RenderModuleFlags(module, key_flags, output_lines, prefix)
-
-  def ModuleHelp(self, module):
-    """Describe the key flags of a module.
-
-    Args:
-      module: A module object or a module name (a string).
-
-    Returns:
-      string describing the key flags of a module.
-    """
-    helplist = []
-    self.__RenderOurModuleKeyFlags(module, helplist)
-    return '\n'.join(helplist)
-
-  def MainModuleHelp(self):
-    """Describe the key flags of the main module.
-
-    Returns:
-      string describing the key flags of a module.
-    """
-    return self.ModuleHelp(_GetMainModule())
-
-  def __RenderFlagList(self, flaglist, output_lines, prefix="  "):
-    fl = self.FlagDict()
-    special_fl = _SPECIAL_FLAGS.FlagDict()
-    flaglist = [(flag.name, flag) for flag in flaglist]
-    flaglist.sort()
-    flagset = {}
-    for (name, flag) in flaglist:
-      # It's possible this flag got deleted or overridden since being
-      # registered in the per-module flaglist.  Check now against the
-      # canonical source of current flag information, the FlagDict.
-      if fl.get(name, None) != flag and special_fl.get(name, None) != flag:
-        # a different flag is using this name now
-        continue
-      # only print help once
-      if flag in flagset: continue
-      flagset[flag] = 1
-      flaghelp = ""
-      if flag.short_name: flaghelp += "-%s," % flag.short_name
-      if flag.boolean:
-        flaghelp += "--[no]%s" % flag.name + ":"
-      else:
-        flaghelp += "--%s" % flag.name + ":"
-      flaghelp += "  "
-      if flag.help:
-        flaghelp += flag.help
-      flaghelp = TextWrap(flaghelp, indent=prefix+"  ",
-                          firstline_indent=prefix)
-      if flag.default_as_str:
-        flaghelp += "\n"
-        flaghelp += TextWrap("(default: %s)" % flag.default_as_str,
-                             indent=prefix+"  ")
-      if flag.parser.syntactic_help:
-        flaghelp += "\n"
-        flaghelp += TextWrap("(%s)" % flag.parser.syntactic_help,
-                             indent=prefix+"  ")
-      output_lines.append(flaghelp)
-
-  def get(self, name, default):
-    """Returns the value of a flag (if not None) or a default value.
-
-    Args:
-      name: A string, the name of a flag.
-      default: Default value to use if the flag value is None.
-    """
-
-    value = self.__getattr__(name)
-    if value is not None:  # Can't do if not value, b/c value might be '0' or ""
-      return value
-    else:
-      return default
-
-  def ShortestUniquePrefixes(self, fl):
-    """Returns: dictionary; maps flag names to their shortest unique prefix."""
-    # Sort the list of flag names
-    sorted_flags = []
-    for name, flag in fl.items():
-      sorted_flags.append(name)
-      if flag.boolean:
-        sorted_flags.append('no%s' % name)
-    sorted_flags.sort()
-
-    # For each name in the sorted list, determine the shortest unique
-    # prefix by comparing itself to the next name and to the previous
-    # name (the latter check uses cached info from the previous loop).
-    shortest_matches = {}
-    prev_idx = 0
-    for flag_idx in range(len(sorted_flags)):
-      curr = sorted_flags[flag_idx]
-      if flag_idx == (len(sorted_flags) - 1):
-        next = None
-      else:
-        next = sorted_flags[flag_idx+1]
-        next_len = len(next)
-      for curr_idx in range(len(curr)):
-        if (next is None
-            or curr_idx >= next_len
-            or curr[curr_idx] != next[curr_idx]):
-          # curr longer than next or no more chars in common
-          shortest_matches[curr] = curr[:max(prev_idx, curr_idx) + 1]
-          prev_idx = curr_idx
-          break
-      else:
-        # curr shorter than (or equal to) next
-        shortest_matches[curr] = curr
-        prev_idx = curr_idx + 1  # next will need at least one more char
-    return shortest_matches
-
-  def __IsFlagFileDirective(self, flag_string):
-    """Checks whether flag_string contain a --flagfile=<foo> directive."""
-    if isinstance(flag_string, type("")):
-      if flag_string.startswith('--flagfile='):
-        return 1
-      elif flag_string == '--flagfile':
-        return 1
-      elif flag_string.startswith('-flagfile='):
-        return 1
-      elif flag_string == '-flagfile':
-        return 1
-      else:
-        return 0
-    return 0
-
-  def ExtractFilename(self, flagfile_str):
-    """Returns filename from a flagfile_str of form -[-]flagfile=filename.
-
-    The cases of --flagfile foo and -flagfile foo shouldn't be hitting
-    this function, as they are dealt with in the level above this
-    function.
-    """
-    if flagfile_str.startswith('--flagfile='):
-      return os.path.expanduser((flagfile_str[(len('--flagfile=')):]).strip())
-    elif flagfile_str.startswith('-flagfile='):
-      return os.path.expanduser((flagfile_str[(len('-flagfile=')):]).strip())
-    else:
-      raise FlagsError('Hit illegal --flagfile type: %s' % flagfile_str)
-
-  def __GetFlagFileLines(self, filename, parsed_file_list):
-    """Returns the useful (!=comments, etc) lines from a file with flags.
-
-    Args:
-      filename: A string, the name of the flag file.
-      parsed_file_list: A list of the names of the files we have
-        already read.  MUTATED BY THIS FUNCTION.
-
-    Returns:
-      List of strings. See the note below.
-
-    NOTE(springer): This function checks for a nested --flagfile=<foo>
-    tag and handles the lower file recursively. It returns a list of
-    all the lines that _could_ contain command flags. This is
-    EVERYTHING except whitespace lines and comments (lines starting
-    with '#' or '//').
-    """
-    line_list = []  # All line from flagfile.
-    flag_line_list = []  # Subset of lines w/o comments, blanks, flagfile= tags.
-    try:
-      file_obj = open(filename, 'r')
-    except IOError, e_msg:
-      raise CantOpenFlagFileError('ERROR:: Unable to open flagfile: %s' % e_msg)
-
-    line_list = file_obj.readlines()
-    file_obj.close()
-    parsed_file_list.append(filename)
-
-    # This is where we check each line in the file we just read.
-    for line in line_list:
-      if line.isspace():
-        pass
-      # Checks for comment (a line that starts with '#').
-      elif line.startswith('#') or line.startswith('//'):
-        pass
-      # Checks for a nested "--flagfile=<bar>" flag in the current file.
-      # If we find one, recursively parse down into that file.
-      elif self.__IsFlagFileDirective(line):
-        sub_filename = self.ExtractFilename(line)
-        # We do a little safety check for reparsing a file we've already done.
-        if not sub_filename in parsed_file_list:
-          included_flags = self.__GetFlagFileLines(sub_filename,
-                                                   parsed_file_list)
-          flag_line_list.extend(included_flags)
-        else:  # Case of hitting a circularly included file.
-          sys.stderr.write('Warning: Hit circular flagfile dependency: %s\n' %
-                           (sub_filename,))
-      else:
-        # Any line that's not a comment or a nested flagfile should get
-        # copied into 2nd position.  This leaves earlier arguments
-        # further back in the list, thus giving them higher priority.
-        flag_line_list.append(line.strip())
-    return flag_line_list
-
-  def ReadFlagsFromFiles(self, argv, force_gnu=True):
-    """Processes command line args, but also allow args to be read from file.
-
-    Args:
-      argv: A list of strings, usually sys.argv[1:], which may contain one or
-        more flagfile directives of the form --flagfile="./filename".
-        Note that the name of the program (sys.argv[0]) should be omitted.
-      force_gnu: If False, --flagfile parsing obeys normal flag semantics.
-        If True, --flagfile parsing instead follows gnu_getopt semantics.
-        *** WARNING *** force_gnu=False may become the future default!
-
-    Returns:
-
-      A new list which has the original list combined with what we read
-      from any flagfile(s).
-
-    References: Global gflags.FLAG class instance.
-
-    This function should be called before the normal FLAGS(argv) call.
-    This function scans the input list for a flag that looks like:
-    --flagfile=<somefile>. Then it opens <somefile>, reads all valid key
-    and value pairs and inserts them into the input list between the
-    first item of the list and any subsequent items in the list.
-
-    Note that your application's flags are still defined the usual way
-    using gflags DEFINE_flag() type functions.
-
-    Notes (assuming we're getting a commandline of some sort as our input):
-    --> Flags from the command line argv _should_ always take precedence!
-    --> A further "--flagfile=<otherfile.cfg>" CAN be nested in a flagfile.
-        It will be processed after the parent flag file is done.
-    --> For duplicate flags, first one we hit should "win".
-    --> In a flagfile, a line beginning with # or // is a comment.
-    --> Entirely blank lines _should_ be ignored.
-    """
-    parsed_file_list = []
-    rest_of_args = argv
-    new_argv = []
-    while rest_of_args:
-      current_arg = rest_of_args[0]
-      rest_of_args = rest_of_args[1:]
-      if self.__IsFlagFileDirective(current_arg):
-        # This handles the case of -(-)flagfile foo.  In this case the
-        # next arg really is part of this one.
-        if current_arg == '--flagfile' or current_arg == '-flagfile':
-          if not rest_of_args:
-            raise IllegalFlagValue('--flagfile with no argument')
-          flag_filename = os.path.expanduser(rest_of_args[0])
-          rest_of_args = rest_of_args[1:]
-        else:
-          # This handles the case of (-)-flagfile=foo.
-          flag_filename = self.ExtractFilename(current_arg)
-        new_argv.extend(
-            self.__GetFlagFileLines(flag_filename, parsed_file_list))
-      else:
-        new_argv.append(current_arg)
-        # Stop parsing after '--', like getopt and gnu_getopt.
-        if current_arg == '--':
-          break
-        # Stop parsing after a non-flag, like getopt.
-        if not current_arg.startswith('-'):
-          if not force_gnu and not self.__dict__['__use_gnu_getopt']:
-            break
-
-    if rest_of_args:
-      new_argv.extend(rest_of_args)
-
-    return new_argv
-
-  def FlagsIntoString(self):
-    """Returns a string with the flags assignments from this FlagValues object.
-
-    This function ignores flags whose value is None.  Each flag
-    assignment is separated by a newline.
-
-    NOTE: MUST mirror the behavior of the C++ CommandlineFlagsIntoString
-    from http://code.google.com/p/google-gflags
-    """
-    s = ''
-    for flag in self.FlagDict().values():
-      if flag.value is not None:
-        s += flag.Serialize() + '\n'
-    return s
-
-  def AppendFlagsIntoFile(self, filename):
-    """Appends all flags assignments from this FlagInfo object to a file.
-
-    Output will be in the format of a flagfile.
-
-    NOTE: MUST mirror the behavior of the C++ AppendFlagsIntoFile
-    from http://code.google.com/p/google-gflags
-    """
-    out_file = open(filename, 'a')
-    out_file.write(self.FlagsIntoString())
-    out_file.close()
-
-  def WriteHelpInXMLFormat(self, outfile=None):
-    """Outputs flag documentation in XML format.
-
-    NOTE: We use element names that are consistent with those used by
-    the C++ command-line flag library, from
-    http://code.google.com/p/google-gflags
-    We also use a few new elements (e.g., <key>), but we do not
-    interfere / overlap with existing XML elements used by the C++
-    library.  Please maintain this consistency.
-
-    Args:
-      outfile: File object we write to.  Default None means sys.stdout.
-    """
-    outfile = outfile or sys.stdout
-
-    outfile.write('<?xml version=\"1.0\"?>\n')
-    outfile.write('<AllFlags>\n')
-    indent = '  '
-    _WriteSimpleXMLElement(outfile, 'program', os.path.basename(sys.argv[0]),
-                           indent)
-
-    usage_doc = sys.modules['__main__'].__doc__
-    if not usage_doc:
-      usage_doc = '\nUSAGE: %s [flags]\n' % sys.argv[0]
-    else:
-      usage_doc = usage_doc.replace('%s', sys.argv[0])
-    _WriteSimpleXMLElement(outfile, 'usage', usage_doc, indent)
-
-    # Get list of key flags for the main module.
-    key_flags = self._GetKeyFlagsForModule(_GetMainModule())
-
-    # Sort flags by declaring module name and next by flag name.
-    flags_by_module = self.FlagsByModuleDict()
-    all_module_names = list(flags_by_module.keys())
-    all_module_names.sort()
-    for module_name in all_module_names:
-      flag_list = [(f.name, f) for f in flags_by_module[module_name]]
-      flag_list.sort()
-      for unused_flag_name, flag in flag_list:
-        is_key = flag in key_flags
-        flag.WriteInfoInXMLFormat(outfile, module_name,
-                                  is_key=is_key, indent=indent)
-
-    outfile.write('</AllFlags>\n')
-    outfile.flush()
-
-  def AddValidator(self, validator):
-    """Register new flags validator to be checked.
-
-    Args:
-      validator: gflags_validators.Validator
-    Raises:
-      AttributeError: if validators work with a non-existing flag.
-    """
-    for flag_name in validator.GetFlagsNames():
-      flag = self.FlagDict()[flag_name]
-      flag.validators.append(validator)
-
-# end of FlagValues definition
-
-
-# The global FlagValues instance
-FLAGS = FlagValues()
-
-
-def _StrOrUnicode(value):
-  """Converts value to a python string or, if necessary, unicode-string."""
-  try:
-    return str(value)
-  except UnicodeEncodeError:
-    return unicode(value)
-
-
-def _MakeXMLSafe(s):
-  """Escapes <, >, and & from s, and removes XML 1.0-illegal chars."""
-  s = cgi.escape(s)  # Escape <, >, and &
-  # Remove characters that cannot appear in an XML 1.0 document
-  # (http://www.w3.org/TR/REC-xml/#charsets).
-  #
-  # NOTE: if there are problems with current solution, one may move to
-  # XML 1.1, which allows such chars, if they're entity-escaped (&#xHH;).
-  s = re.sub(r'[\x00-\x08\x0b\x0c\x0e-\x1f]', '', s)
-  # Convert non-ascii characters to entities.  Note: requires python >=2.3
-  s = s.encode('ascii', 'xmlcharrefreplace')   # u'\xce\x88' -> 'u&#904;'
-  return s
-
-
-def _WriteSimpleXMLElement(outfile, name, value, indent):
-  """Writes a simple XML element.
-
-  Args:
-    outfile: File object we write the XML element to.
-    name: A string, the name of XML element.
-    value: A Python object, whose string representation will be used
-      as the value of the XML element.
-    indent: A string, prepended to each line of generated output.
-  """
-  value_str = _StrOrUnicode(value)
-  if isinstance(value, bool):
-    # Display boolean values as the C++ flag library does: no caps.
-    value_str = value_str.lower()
-  safe_value_str = _MakeXMLSafe(value_str)
-  outfile.write('%s<%s>%s</%s>\n' % (indent, name, safe_value_str, name))
-
-
-class Flag:
-  """Information about a command-line flag.
-
-  'Flag' objects define the following fields:
-    .name  - the name for this flag
-    .default - the default value for this flag
-    .default_as_str - default value as repr'd string, e.g., "'true'" (or None)
-    .value  - the most recent parsed value of this flag; set by Parse()
-    .help  - a help string or None if no help is available
-    .short_name  - the single letter alias for this flag (or None)
-    .boolean  - if 'true', this flag does not accept arguments
-    .present  - true if this flag was parsed from command line flags.
-    .parser  - an ArgumentParser object
-    .serializer - an ArgumentSerializer object
-    .allow_override - the flag may be redefined without raising an error
-
-  The only public method of a 'Flag' object is Parse(), but it is
-  typically only called by a 'FlagValues' object.  The Parse() method is
-  a thin wrapper around the 'ArgumentParser' Parse() method.  The parsed
-  value is saved in .value, and the .present attribute is updated.  If
-  this flag was already present, a FlagsError is raised.
-
-  Parse() is also called during __init__ to parse the default value and
-  initialize the .value attribute.  This enables other python modules to
-  safely use flags even if the __main__ module neglects to parse the
-  command line arguments.  The .present attribute is cleared after
-  __init__ parsing.  If the default value is set to None, then the
-  __init__ parsing step is skipped and the .value attribute is
-  initialized to None.
-
-  Note: The default value is also presented to the user in the help
-  string, so it is important that it be a legal value for this flag.
-  """
-
-  def __init__(self, parser, serializer, name, default, help_string,
-               short_name=None, boolean=0, allow_override=0):
-    self.name = name
-
-    if not help_string:
-      help_string = '(no help available)'
-
-    self.help = help_string
-    self.short_name = short_name
-    self.boolean = boolean
-    self.present = 0
-    self.parser = parser
-    self.serializer = serializer
-    self.allow_override = allow_override
-    self.value = None
-    self.validators = []
-
-    self.SetDefault(default)
-
-  def __hash__(self):
-    return hash(id(self))
-
-  def __eq__(self, other):
-    return self is other
-
-  def __lt__(self, other):
-    if isinstance(other, Flag):
-      return id(self) < id(other)
-    return NotImplemented
-
-  def __GetParsedValueAsString(self, value):
-    if value is None:
-      return None
-    if self.serializer:
-      return repr(self.serializer.Serialize(value))
-    if self.boolean:
-      if value:
-        return repr('true')
-      else:
-        return repr('false')
-    return repr(_StrOrUnicode(value))
-
-  def Parse(self, argument):
-    try:
-      self.value = self.parser.Parse(argument)
-    except ValueError, e:  # recast ValueError as IllegalFlagValue
-      raise IllegalFlagValue("flag --%s=%s: %s" % (self.name, argument, e))
-    self.present += 1
-
-  def Unparse(self):
-    if self.default is None:
-      self.value = None
-    else:
-      self.Parse(self.default)
-    self.present = 0
-
-  def Serialize(self):
-    if self.value is None:
-      return ''
-    if self.boolean:
-      if self.value:
-        return "--%s" % self.name
-      else:
-        return "--no%s" % self.name
-    else:
-      if not self.serializer:
-        raise FlagsError("Serializer not present for flag %s" % self.name)
-      return "--%s=%s" % (self.name, self.serializer.Serialize(self.value))
-
-  def SetDefault(self, value):
-    """Changes the default value (and current value too) for this Flag."""
-    # We can't allow a None override because it may end up not being
-    # passed to C++ code when we're overriding C++ flags.  So we
-    # cowardly bail out until someone fixes the semantics of trying to
-    # pass None to a C++ flag.  See swig_flags.Init() for details on
-    # this behavior.
-    # TODO(olexiy): Users can directly call this method, bypassing all flags
-    # validators (we don't have FlagValues here, so we can not check
-    # validators).
-    # The simplest solution I see is to make this method private.
-    # Another approach would be to store reference to the corresponding
-    # FlagValues with each flag, but this seems to be an overkill.
-    if value is None and self.allow_override:
-      raise DuplicateFlagCannotPropagateNoneToSwig(self.name)
-
-    self.default = value
-    self.Unparse()
-    self.default_as_str = self.__GetParsedValueAsString(self.value)
-
-  def Type(self):
-    """Returns: a string that describes the type of this Flag."""
-    # NOTE: we use strings, and not the types.*Type constants because
-    # our flags can have more exotic types, e.g., 'comma separated list
-    # of strings', 'whitespace separated list of strings', etc.
-    return self.parser.Type()
-
-  def WriteInfoInXMLFormat(self, outfile, module_name, is_key=False, indent=''):
-    """Writes common info about this flag, in XML format.
-
-    This is information that is relevant to all flags (e.g., name,
-    meaning, etc.).  If you defined a flag that has some other pieces of
-    info, then please override _WriteCustomInfoInXMLFormat.
-
-    Please do NOT override this method.
-
-    Args:
-      outfile: File object we write to.
-      module_name: A string, the name of the module that defines this flag.
-      is_key: A boolean, True iff this flag is key for main module.
-      indent: A string that is prepended to each generated line.
-    """
-    outfile.write(indent + '<flag>\n')
-    inner_indent = indent + '  '
-    if is_key:
-      _WriteSimpleXMLElement(outfile, 'key', 'yes', inner_indent)
-    _WriteSimpleXMLElement(outfile, 'file', module_name, inner_indent)
-    # Print flag features that are relevant for all flags.
-    _WriteSimpleXMLElement(outfile, 'name', self.name, inner_indent)
-    if self.short_name:
-      _WriteSimpleXMLElement(outfile, 'short_name', self.short_name,
-                             inner_indent)
-    if self.help:
-      _WriteSimpleXMLElement(outfile, 'meaning', self.help, inner_indent)
-    # The default flag value can either be represented as a string like on the
-    # command line, or as a Python object.  We serialize this value in the
-    # latter case in order to remain consistent.
-    if self.serializer and not isinstance(self.default, str):
-      default_serialized = self.serializer.Serialize(self.default)
-    else:
-      default_serialized = self.default
-    _WriteSimpleXMLElement(outfile, 'default', default_serialized, inner_indent)
-    _WriteSimpleXMLElement(outfile, 'current', self.value, inner_indent)
-    _WriteSimpleXMLElement(outfile, 'type', self.Type(), inner_indent)
-    # Print extra flag features this flag may have.
-    self._WriteCustomInfoInXMLFormat(outfile, inner_indent)
-    outfile.write(indent + '</flag>\n')
-
-  def _WriteCustomInfoInXMLFormat(self, outfile, indent):
-    """Writes extra info about this flag, in XML format.
-
-    "Extra" means "not already printed by WriteInfoInXMLFormat above."
-
-    Args:
-      outfile: File object we write to.
-      indent: A string that is prepended to each generated line.
-    """
-    # Usually, the parser knows the extra details about the flag, so
-    # we just forward the call to it.
-    self.parser.WriteCustomInfoInXMLFormat(outfile, indent)
-# End of Flag definition
-
-
-class _ArgumentParserCache(type):
-  """Metaclass used to cache and share argument parsers among flags."""
-
-  _instances = {}
-
-  def __call__(mcs, *args, **kwargs):
-    """Returns an instance of the argument parser cls.
-
-    This method overrides behavior of the __new__ methods in
-    all subclasses of ArgumentParser (inclusive). If an instance
-    for mcs with the same set of arguments exists, this instance is
-    returned, otherwise a new instance is created.
-
-    If any keyword arguments are defined, or the values in args
-    are not hashable, this method always returns a new instance of
-    cls.
-
-    Args:
-      args: Positional initializer arguments.
-      kwargs: Initializer keyword arguments.
-
-    Returns:
-      An instance of cls, shared or new.
-    """
-    if kwargs:
-      return type.__call__(mcs, *args, **kwargs)
-    else:
-      instances = mcs._instances
-      key = (mcs,) + tuple(args)
-      try:
-        return instances[key]
-      except KeyError:
-        # No cache entry for key exists, create a new one.
-        return instances.setdefault(key, type.__call__(mcs, *args))
-      except TypeError:
-        # An object in args cannot be hashed, always return
-        # a new instance.
-        return type.__call__(mcs, *args)
-
-
-class ArgumentParser(object):
-  """Base class used to parse and convert arguments.
-
-  The Parse() method checks to make sure that the string argument is a
-  legal value and convert it to a native type.  If the value cannot be
-  converted, it should throw a 'ValueError' exception with a human
-  readable explanation of why the value is illegal.
-
-  Subclasses should also define a syntactic_help string which may be
-  presented to the user to describe the form of the legal values.
-
-  Argument parser classes must be stateless, since instances are cached
-  and shared between flags. Initializer arguments are allowed, but all
-  member variables must be derived from initializer arguments only.
-  """
-  __metaclass__ = _ArgumentParserCache
-
-  syntactic_help = ""
-
-  def Parse(self, argument):
-    """Default implementation: always returns its argument unmodified."""
-    return argument
-
-  def Type(self):
-    return 'string'
-
-  def WriteCustomInfoInXMLFormat(self, outfile, indent):
-    pass
-
-
-class ArgumentSerializer:
-  """Base class for generating string representations of a flag value."""
-
-  def Serialize(self, value):
-    return _StrOrUnicode(value)
-
-
-class ListSerializer(ArgumentSerializer):
-
-  def __init__(self, list_sep):
-    self.list_sep = list_sep
-
-  def Serialize(self, value):
-    return self.list_sep.join([_StrOrUnicode(x) for x in value])
-
-
-# Flags validators
-
-
-def RegisterValidator(flag_name,
-                      checker,
-                      message='Flag validation failed',
-                      flag_values=FLAGS):
-  """Adds a constraint, which will be enforced during program execution.
-
-  The constraint is validated when flags are initially parsed, and after each
-  change of the corresponding flag's value.
-  Args:
-    flag_name: string, name of the flag to be checked.
-    checker: method to validate the flag.
-      input  - value of the corresponding flag (string, boolean, etc.
-        This value will be passed to checker by the library). See file's
-        docstring for examples.
-      output - Boolean.
-        Must return True if validator constraint is satisfied.
-        If constraint is not satisfied, it should either return False or
-          raise gflags_validators.Error(desired_error_message).
-    message: error text to be shown to the user if checker returns False.
-      If checker raises gflags_validators.Error, message from the raised
-        Error will be shown.
-    flag_values: FlagValues
-  Raises:
-    AttributeError: if flag_name is not registered as a valid flag name.
-  """
-  flag_values.AddValidator(gflags_validators.SimpleValidator(flag_name,
-                                                            checker,
-                                                            message))
-
-
-def MarkFlagAsRequired(flag_name, flag_values=FLAGS):
-  """Ensure that flag is not None during program execution.
-
-  Registers a flag validator, which will follow usual validator
-  rules.
-  Args:
-    flag_name: string, name of the flag
-    flag_values: FlagValues
-  Raises:
-    AttributeError: if flag_name is not registered as a valid flag name.
-  """
-  RegisterValidator(flag_name,
-                    lambda value: value is not None,
-                    message='Flag --%s must be specified.' % flag_name,
-                    flag_values=flag_values)
-
-
-def _RegisterBoundsValidatorIfNeeded(parser, name, flag_values):
-  """Enforce lower and upper bounds for numeric flags.
-
-  Args:
-    parser: NumericParser (either FloatParser or IntegerParser). Provides lower
-      and upper bounds, and help text to display.
-    name: string, name of the flag
-    flag_values: FlagValues
-  """
-  if parser.lower_bound is not None or parser.upper_bound is not None:
-
-    def Checker(value):
-      if value is not None and parser.IsOutsideBounds(value):
-        message = '%s is not %s' % (value, parser.syntactic_help)
-        raise gflags_validators.Error(message)
-      return True
-
-    RegisterValidator(name,
-                      Checker,
-                      flag_values=flag_values)
-
-
-# The DEFINE functions are explained in mode details in the module doc string.
-
-
-def DEFINE(parser, name, default, help, flag_values=FLAGS, serializer=None,
-           **args):
-  """Registers a generic Flag object.
-
-  NOTE: in the docstrings of all DEFINE* functions, "registers" is short
-  for "creates a new flag and registers it".
-
-  Auxiliary function: clients should use the specialized DEFINE_<type>
-  function instead.
-
-  Args:
-    parser: ArgumentParser that is used to parse the flag arguments.
-    name: A string, the flag name.
-    default: The default value of the flag.
-    help: A help string.
-    flag_values: FlagValues object the flag will be registered with.
-    serializer: ArgumentSerializer that serializes the flag value.
-    args: Dictionary with extra keyword args that are passes to the
-      Flag __init__.
-  """
-  DEFINE_flag(Flag(parser, serializer, name, default, help, **args),
-              flag_values)
-
-
-def DEFINE_flag(flag, flag_values=FLAGS):
-  """Registers a 'Flag' object with a 'FlagValues' object.
-
-  By default, the global FLAGS 'FlagValue' object is used.
-
-  Typical users will use one of the more specialized DEFINE_xxx
-  functions, such as DEFINE_string or DEFINE_integer.  But developers
-  who need to create Flag objects themselves should use this function
-  to register their flags.
-  """
-  # copying the reference to flag_values prevents pychecker warnings
-  fv = flag_values
-  fv[flag.name] = flag
-  # Tell flag_values who's defining the flag.
-  if isinstance(flag_values, FlagValues):
-    # Regarding the above isinstance test: some users pass funny
-    # values of flag_values (e.g., {}) in order to avoid the flag
-    # registration (in the past, there used to be a flag_values ==
-    # FLAGS test here) and redefine flags with the same name (e.g.,
-    # debug).  To avoid breaking their code, we perform the
-    # registration only if flag_values is a real FlagValues object.
-    module, module_name = _GetCallingModuleObjectAndName()
-    flag_values._RegisterFlagByModule(module_name, flag)
-    flag_values._RegisterFlagByModuleId(id(module), flag)
-
-
-def _InternalDeclareKeyFlags(flag_names,
-                             flag_values=FLAGS, key_flag_values=None):
-  """Declares a flag as key for the calling module.
-
-  Internal function.  User code should call DECLARE_key_flag or
-  ADOPT_module_key_flags instead.
-
-  Args:
-    flag_names: A list of strings that are names of already-registered
-      Flag objects.
-    flag_values: A FlagValues object that the flags listed in
-      flag_names have registered with (the value of the flag_values
-      argument from the DEFINE_* calls that defined those flags).
-      This should almost never need to be overridden.
-    key_flag_values: A FlagValues object that (among possibly many
-      other things) keeps track of the key flags for each module.
-      Default None means "same as flag_values".  This should almost
-      never need to be overridden.
-
-  Raises:
-    UnrecognizedFlagError: when we refer to a flag that was not
-      defined yet.
-  """
-  key_flag_values = key_flag_values or flag_values
-
-  module = _GetCallingModule()
-
-  for flag_name in flag_names:
-    if flag_name not in flag_values:
-      raise UnrecognizedFlagError(flag_name)
-    flag = flag_values.FlagDict()[flag_name]
-    key_flag_values._RegisterKeyFlagForModule(module, flag)
-
-
-def DECLARE_key_flag(flag_name, flag_values=FLAGS):
-  """Declares one flag as key to the current module.
-
-  Key flags are flags that are deemed really important for a module.
-  They are important when listing help messages; e.g., if the
-  --helpshort command-line flag is used, then only the key flags of the
-  main module are listed (instead of all flags, as in the case of
-  --help).
-
-  Sample usage:
-
-    gflags.DECLARED_key_flag('flag_1')
-
-  Args:
-    flag_name: A string, the name of an already declared flag.
-      (Redeclaring flags as key, including flags implicitly key
-      because they were declared in this module, is a no-op.)
-    flag_values: A FlagValues object.  This should almost never
-      need to be overridden.
-  """
-  if flag_name in _SPECIAL_FLAGS:
-    # Take care of the special flags, e.g., --flagfile, --undefok.
-    # These flags are defined in _SPECIAL_FLAGS, and are treated
-    # specially during flag parsing, taking precedence over the
-    # user-defined flags.
-    _InternalDeclareKeyFlags([flag_name],
-                             flag_values=_SPECIAL_FLAGS,
-                             key_flag_values=flag_values)
-    return
-  _InternalDeclareKeyFlags([flag_name], flag_values=flag_values)
-
-
-def ADOPT_module_key_flags(module, flag_values=FLAGS):
-  """Declares that all flags key to a module are key to the current module.
-
-  Args:
-    module: A module object.
-    flag_values: A FlagValues object.  This should almost never need
-      to be overridden.
-
-  Raises:
-    FlagsError: When given an argument that is a module name (a
-    string), instead of a module object.
-  """
-  # NOTE(salcianu): an even better test would be if not
-  # isinstance(module, types.ModuleType) but I didn't want to import
-  # types for such a tiny use.
-  if isinstance(module, str):
-    raise FlagsError('Received module name %s; expected a module object.'
-                     % module)
-  _InternalDeclareKeyFlags(
-      [f.name for f in flag_values._GetKeyFlagsForModule(module.__name__)],
-      flag_values=flag_values)
-  # If module is this flag module, take _SPECIAL_FLAGS into account.
-  if module == _GetThisModuleObjectAndName()[0]:
-    _InternalDeclareKeyFlags(
-        # As we associate flags with _GetCallingModuleObjectAndName(), the
-        # special flags defined in this module are incorrectly registered with
-        # a different module.  So, we can't use _GetKeyFlagsForModule.
-        # Instead, we take all flags from _SPECIAL_FLAGS (a private
-        # FlagValues, where no other module should register flags).
-        [f.name for f in _SPECIAL_FLAGS.FlagDict().values()],
-        flag_values=_SPECIAL_FLAGS,
-        key_flag_values=flag_values)
-
-
-#
-# STRING FLAGS
-#
-
-
-def DEFINE_string(name, default, help, flag_values=FLAGS, **args):
-  """Registers a flag whose value can be any string."""
-  parser = ArgumentParser()
-  serializer = ArgumentSerializer()
-  DEFINE(parser, name, default, help, flag_values, serializer, **args)
-
-
-#
-# BOOLEAN FLAGS
-#
-
-
-class BooleanParser(ArgumentParser):
-  """Parser of boolean values."""
-
-  def Convert(self, argument):
-    """Converts the argument to a boolean; raise ValueError on errors."""
-    if type(argument) == str:
-      if argument.lower() in ['true', 't', '1']:
-        return True
-      elif argument.lower() in ['false', 'f', '0']:
-        return False
-
-    bool_argument = bool(argument)
-    if argument == bool_argument:
-      # The argument is a valid boolean (True, False, 0, or 1), and not just
-      # something that always converts to bool (list, string, int, etc.).
-      return bool_argument
-
-    raise ValueError('Non-boolean argument to boolean flag', argument)
-
-  def Parse(self, argument):
-    val = self.Convert(argument)
-    return val
-
-  def Type(self):
-    return 'bool'
-
-
-class BooleanFlag(Flag):
-  """Basic boolean flag.
-
-  Boolean flags do not take any arguments, and their value is either
-  True (1) or False (0).  The false value is specified on the command
-  line by prepending the word 'no' to either the long or the short flag
-  name.
-
-  For example, if a Boolean flag was created whose long name was
-  'update' and whose short name was 'x', then this flag could be
-  explicitly unset through either --noupdate or --nox.
-  """
-
-  def __init__(self, name, default, help, short_name=None, **args):
-    p = BooleanParser()
-    Flag.__init__(self, p, None, name, default, help, short_name, 1, **args)
-    if not self.help: self.help = "a boolean value"
-
-
-def DEFINE_boolean(name, default, help, flag_values=FLAGS, **args):
-  """Registers a boolean flag.
-
-  Such a boolean flag does not take an argument.  If a user wants to
-  specify a false value explicitly, the long option beginning with 'no'
-  must be used: i.e. --noflag
-
-  This flag will have a value of None, True or False.  None is possible
-  if default=None and the user does not specify the flag on the command
-  line.
-  """
-  DEFINE_flag(BooleanFlag(name, default, help, **args), flag_values)
-
-
-# Match C++ API to unconfuse C++ people.
-DEFINE_bool = DEFINE_boolean
-
-
-class HelpFlag(BooleanFlag):
-  """
-  HelpFlag is a special boolean flag that prints usage information and
-  raises a SystemExit exception if it is ever found in the command
-  line arguments.  Note this is called with allow_override=1, so other
-  apps can define their own --help flag, replacing this one, if they want.
-  """
-  def __init__(self):
-    BooleanFlag.__init__(self, "help", 0, "show this help",
-                         short_name="?", allow_override=1)
-  def Parse(self, arg):
-    if arg:
-      doc = sys.modules["__main__"].__doc__
-      flags = str(FLAGS)
-      print doc or ("\nUSAGE: %s [flags]\n" % sys.argv[0])
-      if flags:
-        print "flags:"
-        print flags
-      sys.exit(1)
-class HelpXMLFlag(BooleanFlag):
-  """Similar to HelpFlag, but generates output in XML format."""
-  def __init__(self):
-    BooleanFlag.__init__(self, 'helpxml', False,
-                         'like --help, but generates XML output',
-                         allow_override=1)
-  def Parse(self, arg):
-    if arg:
-      FLAGS.WriteHelpInXMLFormat(sys.stdout)
-      sys.exit(1)
-class HelpshortFlag(BooleanFlag):
-  """
-  HelpshortFlag is a special boolean flag that prints usage
-  information for the "main" module, and rasies a SystemExit exception
-  if it is ever found in the command line arguments.  Note this is
-  called with allow_override=1, so other apps can define their own
-  --helpshort flag, replacing this one, if they want.
-  """
-  def __init__(self):
-    BooleanFlag.__init__(self, "helpshort", 0,
-                         "show usage only for this module", allow_override=1)
-  def Parse(self, arg):
-    if arg:
-      doc = sys.modules["__main__"].__doc__
-      flags = FLAGS.MainModuleHelp()
-      print doc or ("\nUSAGE: %s [flags]\n" % sys.argv[0])
-      if flags:
-        print "flags:"
-        print flags
-      sys.exit(1)
-
-#
-# Numeric parser - base class for Integer and Float parsers
-#
-
-
-class NumericParser(ArgumentParser):
-  """Parser of numeric values.
-
-  Parsed value may be bounded to a given upper and lower bound.
-  """
-
-  def IsOutsideBounds(self, val):
-    return ((self.lower_bound is not None and val < self.lower_bound) or
-            (self.upper_bound is not None and val > self.upper_bound))
-
-  def Parse(self, argument):
-    val = self.Convert(argument)
-    if self.IsOutsideBounds(val):
-      raise ValueError("%s is not %s" % (val, self.syntactic_help))
-    return val
-
-  def WriteCustomInfoInXMLFormat(self, outfile, indent):
-    if self.lower_bound is not None:
-      _WriteSimpleXMLElement(outfile, 'lower_bound', self.lower_bound, indent)
-    if self.upper_bound is not None:
-      _WriteSimpleXMLElement(outfile, 'upper_bound', self.upper_bound, indent)
-
-  def Convert(self, argument):
-    """Default implementation: always returns its argument unmodified."""
-    return argument
-
-# End of Numeric Parser
-
-#
-# FLOAT FLAGS
-#
-
-
-class FloatParser(NumericParser):
-  """Parser of floating point values.
-
-  Parsed value may be bounded to a given upper and lower bound.
-  """
-  number_article = "a"
-  number_name = "number"
-  syntactic_help = " ".join((number_article, number_name))
-
-  def __init__(self, lower_bound=None, upper_bound=None):
-    super(FloatParser, self).__init__()
-    self.lower_bound = lower_bound
-    self.upper_bound = upper_bound
-    sh = self.syntactic_help
-    if lower_bound is not None and upper_bound is not None:
-      sh = ("%s in the range [%s, %s]" % (sh, lower_bound, upper_bound))
-    elif lower_bound == 0:
-      sh = "a non-negative %s" % self.number_name
-    elif upper_bound == 0:
-      sh = "a non-positive %s" % self.number_name
-    elif upper_bound is not None:
-      sh = "%s <= %s" % (self.number_name, upper_bound)
-    elif lower_bound is not None:
-      sh = "%s >= %s" % (self.number_name, lower_bound)
-    self.syntactic_help = sh
-
-  def Convert(self, argument):
-    """Converts argument to a float; raises ValueError on errors."""
-    return float(argument)
-
-  def Type(self):
-    return 'float'
-# End of FloatParser
-
-
-def DEFINE_float(name, default, help, lower_bound=None, upper_bound=None,
-                 flag_values=FLAGS, **args):
-  """Registers a flag whose value must be a float.
-
-  If lower_bound or upper_bound are set, then this flag must be
-  within the given range.
-  """
-  parser = FloatParser(lower_bound, upper_bound)
-  serializer = ArgumentSerializer()
-  DEFINE(parser, name, default, help, flag_values, serializer, **args)
-  _RegisterBoundsValidatorIfNeeded(parser, name, flag_values=flag_values)
-
-#
-# INTEGER FLAGS
-#
-
-
-class IntegerParser(NumericParser):
-  """Parser of an integer value.
-
-  Parsed value may be bounded to a given upper and lower bound.
-  """
-  number_article = "an"
-  number_name = "integer"
-  syntactic_help = " ".join((number_article, number_name))
-
-  def __init__(self, lower_bound=None, upper_bound=None):
-    super(IntegerParser, self).__init__()
-    self.lower_bound = lower_bound
-    self.upper_bound = upper_bound
-    sh = self.syntactic_help
-    if lower_bound is not None and upper_bound is not None:
-      sh = ("%s in the range [%s, %s]" % (sh, lower_bound, upper_bound))
-    elif lower_bound == 1:
-      sh = "a positive %s" % self.number_name
-    elif upper_bound == -1:
-      sh = "a negative %s" % self.number_name
-    elif lower_bound == 0:
-      sh = "a non-negative %s" % self.number_name
-    elif upper_bound == 0:
-      sh = "a non-positive %s" % self.number_name
-    elif upper_bound is not None:
-      sh = "%s <= %s" % (self.number_name, upper_bound)
-    elif lower_bound is not None:
-      sh = "%s >= %s" % (self.number_name, lower_bound)
-    self.syntactic_help = sh
-
-  def Convert(self, argument):
-    __pychecker__ = 'no-returnvalues'
-    if type(argument) == str:
-      base = 10
-      if len(argument) > 2 and argument[0] == "0" and argument[1] == "x":
-        base = 16
-      return int(argument, base)
-    else:
-      return int(argument)
-
-  def Type(self):
-    return 'int'
-
-
-def DEFINE_integer(name, default, help, lower_bound=None, upper_bound=None,
-                   flag_values=FLAGS, **args):
-  """Registers a flag whose value must be an integer.
-
-  If lower_bound, or upper_bound are set, then this flag must be
-  within the given range.
-  """
-  parser = IntegerParser(lower_bound, upper_bound)
-  serializer = ArgumentSerializer()
-  DEFINE(parser, name, default, help, flag_values, serializer, **args)
-  _RegisterBoundsValidatorIfNeeded(parser, name, flag_values=flag_values)
-
-
-#
-# ENUM FLAGS
-#
-
-
-class EnumParser(ArgumentParser):
-  """Parser of a string enum value (a string value from a given set).
-
-  If enum_values (see below) is not specified, any string is allowed.
-  """
-
-  def __init__(self, enum_values=None):
-    super(EnumParser, self).__init__()
-    self.enum_values = enum_values
-
-  def Parse(self, argument):
-    if self.enum_values and argument not in self.enum_values:
-      raise ValueError("value should be one of <%s>" %
-                       "|".join(self.enum_values))
-    return argument
-
-  def Type(self):
-    return 'string enum'
-
-
-class EnumFlag(Flag):
-  """Basic enum flag; its value can be any string from list of enum_values."""
-
-  def __init__(self, name, default, help, enum_values=None,
-               short_name=None, **args):
-    enum_values = enum_values or []
-    p = EnumParser(enum_values)
-    g = ArgumentSerializer()
-    Flag.__init__(self, p, g, name, default, help, short_name, **args)
-    if not self.help: self.help = "an enum string"
-    self.help = "<%s>: %s" % ("|".join(enum_values), self.help)
-
-  def _WriteCustomInfoInXMLFormat(self, outfile, indent):
-    for enum_value in self.parser.enum_values:
-      _WriteSimpleXMLElement(outfile, 'enum_value', enum_value, indent)
-
-
-def DEFINE_enum(name, default, enum_values, help, flag_values=FLAGS,
-                **args):
-  """Registers a flag whose value can be any string from enum_values."""
-  DEFINE_flag(EnumFlag(name, default, help, enum_values, ** args),
-              flag_values)
-
-
-#
-# LIST FLAGS
-#
-
-
-class BaseListParser(ArgumentParser):
-  """Base class for a parser of lists of strings.
-
-  To extend, inherit from this class; from the subclass __init__, call
-
-    BaseListParser.__init__(self, token, name)
-
-  where token is a character used to tokenize, and name is a description
-  of the separator.
-  """
-
-  def __init__(self, token=None, name=None):
-    assert name
-    super(BaseListParser, self).__init__()
-    self._token = token
-    self._name = name
-    self.syntactic_help = "a %s separated list" % self._name
-
-  def Parse(self, argument):
-    if isinstance(argument, list):
-      return argument
-    elif argument == '':
-      return []
-    else:
-      return [s.strip() for s in argument.split(self._token)]
-
-  def Type(self):
-    return '%s separated list of strings' % self._name
-
-
-class ListParser(BaseListParser):
-  """Parser for a comma-separated list of strings."""
-
-  def __init__(self):
-    BaseListParser.__init__(self, ',', 'comma')
-
-  def WriteCustomInfoInXMLFormat(self, outfile, indent):
-    BaseListParser.WriteCustomInfoInXMLFormat(self, outfile, indent)
-    _WriteSimpleXMLElement(outfile, 'list_separator', repr(','), indent)
-
-
-class WhitespaceSeparatedListParser(BaseListParser):
-  """Parser for a whitespace-separated list of strings."""
-
-  def __init__(self):
-    BaseListParser.__init__(self, None, 'whitespace')
-
-  def WriteCustomInfoInXMLFormat(self, outfile, indent):
-    BaseListParser.WriteCustomInfoInXMLFormat(self, outfile, indent)
-    separators = list(string.whitespace)
-    separators.sort()
-    for ws_char in string.whitespace:
-      _WriteSimpleXMLElement(outfile, 'list_separator', repr(ws_char), indent)
-
-
-def DEFINE_list(name, default, help, flag_values=FLAGS, **args):
-  """Registers a flag whose value is a comma-separated list of strings."""
-  parser = ListParser()
-  serializer = ListSerializer(',')
-  DEFINE(parser, name, default, help, flag_values, serializer, **args)
-
-
-def DEFINE_spaceseplist(name, default, help, flag_values=FLAGS, **args):
-  """Registers a flag whose value is a whitespace-separated list of strings.
-
-  Any whitespace can be used as a separator.
-  """
-  parser = WhitespaceSeparatedListParser()
-  serializer = ListSerializer(' ')
-  DEFINE(parser, name, default, help, flag_values, serializer, **args)
-
-
-#
-# MULTI FLAGS
-#
-
-
-class MultiFlag(Flag):
-  """A flag that can appear multiple time on the command-line.
-
-  The value of such a flag is a list that contains the individual values
-  from all the appearances of that flag on the command-line.
-
-  See the __doc__ for Flag for most behavior of this class.  Only
-  differences in behavior are described here:
-
-    * The default value may be either a single value or a list of values.
-      A single value is interpreted as the [value] singleton list.
-
-    * The value of the flag is always a list, even if the option was
-      only supplied once, and even if the default value is a single
-      value
-  """
-
-  def __init__(self, *args, **kwargs):
-    Flag.__init__(self, *args, **kwargs)
-    self.help += ';\n    repeat this option to specify a list of values'
-
-  def Parse(self, arguments):
-    """Parses one or more arguments with the installed parser.
-
-    Args:
-      arguments: a single argument or a list of arguments (typically a
-        list of default values); a single argument is converted
-        internally into a list containing one item.
-    """
-    if not isinstance(arguments, list):
-      # Default value may be a list of values.  Most other arguments
-      # will not be, so convert them into a single-item list to make
-      # processing simpler below.
-      arguments = [arguments]
-
-    if self.present:
-      # keep a backup reference to list of previously supplied option values
-      values = self.value
-    else:
-      # "erase" the defaults with an empty list
-      values = []
-
-    for item in arguments:
-      # have Flag superclass parse argument, overwriting self.value reference
-      Flag.Parse(self, item)  # also increments self.present
-      values.append(self.value)
-
-    # put list of option values back in the 'value' attribute
-    self.value = values
-
-  def Serialize(self):
-    if not self.serializer:
-      raise FlagsError("Serializer not present for flag %s" % self.name)
-    if self.value is None:
-      return ''
-
-    s = ''
-
-    multi_value = self.value
-
-    for self.value in multi_value:
-      if s: s += ' '
-      s += Flag.Serialize(self)
-
-    self.value = multi_value
-
-    return s
-
-  def Type(self):
-    return 'multi ' + self.parser.Type()
-
-
-def DEFINE_multi(parser, serializer, name, default, help, flag_values=FLAGS,
-                 **args):
-  """Registers a generic MultiFlag that parses its args with a given parser.
-
-  Auxiliary function.  Normal users should NOT use it directly.
-
-  Developers who need to create their own 'Parser' classes for options
-  which can appear multiple times can call this module function to
-  register their flags.
-  """
-  DEFINE_flag(MultiFlag(parser, serializer, name, default, help, **args),
-              flag_values)
-
-
-def DEFINE_multistring(name, default, help, flag_values=FLAGS, **args):
-  """Registers a flag whose value can be a list of any strings.
-
-  Use the flag on the command line multiple times to place multiple
-  string values into the list.  The 'default' may be a single string
-  (which will be converted into a single-element list) or a list of
-  strings.
-  """
-  parser = ArgumentParser()
-  serializer = ArgumentSerializer()
-  DEFINE_multi(parser, serializer, name, default, help, flag_values, **args)
-
-
-def DEFINE_multi_int(name, default, help, lower_bound=None, upper_bound=None,
-                     flag_values=FLAGS, **args):
-  """Registers a flag whose value can be a list of arbitrary integers.
-
-  Use the flag on the command line multiple times to place multiple
-  integer values into the list.  The 'default' may be a single integer
-  (which will be converted into a single-element list) or a list of
-  integers.
-  """
-  parser = IntegerParser(lower_bound, upper_bound)
-  serializer = ArgumentSerializer()
-  DEFINE_multi(parser, serializer, name, default, help, flag_values, **args)
-
-
-def DEFINE_multi_float(name, default, help, lower_bound=None, upper_bound=None,
-                       flag_values=FLAGS, **args):
-  """Registers a flag whose value can be a list of arbitrary floats.
-
-  Use the flag on the command line multiple times to place multiple
-  float values into the list.  The 'default' may be a single float
-  (which will be converted into a single-element list) or a list of
-  floats.
-  """
-  parser = FloatParser(lower_bound, upper_bound)
-  serializer = ArgumentSerializer()
-  DEFINE_multi(parser, serializer, name, default, help, flag_values, **args)
-
-
-# Now register the flags that we want to exist in all applications.
-# These are all defined with allow_override=1, so user-apps can use
-# these flagnames for their own purposes, if they want.
-DEFINE_flag(HelpFlag())
-DEFINE_flag(HelpshortFlag())
-DEFINE_flag(HelpXMLFlag())
-
-# Define special flags here so that help may be generated for them.
-# NOTE: Please do NOT use _SPECIAL_FLAGS from outside this module.
-_SPECIAL_FLAGS = FlagValues()
-
-
-DEFINE_string(
-    'flagfile', "",
-    "Insert flag definitions from the given file into the command line.",
-    _SPECIAL_FLAGS)
-
-DEFINE_string(
-    'undefok', "",
-    "comma-separated list of flag names that it is okay to specify "
-    "on the command line even if the program does not define a flag "
-    "with that name.  IMPORTANT: flags in this list that have "
-    "arguments MUST use the --flag=value format.", _SPECIAL_FLAGS)