There is a cyclic import in dmprof

tools/deep_memory_profiler/lib/dump.py

 # Copyright 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import logging
-import os
-
 
 LOGGER = logging.getLogger('dmprof')
 
 
 class Dump(object):
   """Represents a heap profile dump."""
   def __init__(self):
     pass
 
   @property
@@ skipping 46 matching lines @@
     Args:
         path: A file path string to load.
         log_header: A preceding string for log messages.
 
     Returns:
         A loaded Dump object.
 
     Raises:
         ParsingException for invalid heap profile dumps.
     """
-    from lib.deep_dump import DeepDump
-    dump = DeepDump(path, os.stat(path).st_mtime)
-    with open(path, 'r') as f:
-      dump.load_file(f, log_header)
-    return dump
-
-
-class DumpList(object):
-  """Represents a sequence of heap profile dumps.
-
-  Individual dumps are loaded into memory lazily as the sequence is accessed,
-  either while being iterated through or randomly accessed.  Loaded dumps are
-  not cached, meaning a newly loaded Dump object is returned every time an
-  element in the list is accessed.
-  """
-
-  def __init__(self, dump_path_list):
-    self._dump_path_list = dump_path_list
-
-  @staticmethod
-  def load(path_list):
-    return DumpList(path_list)
-
-  def __len__(self):
-    return len(self._dump_path_list)
-
-  def __iter__(self):
-    for dump in self._dump_path_list:
-      yield Dump.load(dump)
-
-  def __getitem__(self, index):
-    return Dump.load(self._dump_path_list[index])
+    raise NotImplementedError