Add a [hide] argument to [ArgParser.addFlag].

pkg/args/lib/args.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /**
  * Parser support for transforming raw command-line arguments into a set
  * of options and values.
  *
  * This library supports [GNU][] and [POSIX][] style options, and it works
  * in both server-side and client-side apps.
@@ skipping 303 matching lines @@
     return parser;
   }
 
   /**
    * Defines a flag. Throws an [ArgumentError] if:
    *
    * * There is already an option named [name].
    * * There is already an option using abbreviation [abbr].
    */
   void addFlag(String name, {String abbr, String help, bool defaultsTo: false,
-      bool negatable: true, void callback(bool value)}) {
+      bool negatable: true, void callback(bool value), bool hide: false}) {
     _addOption(name, abbr, help, null, null, defaultsTo, callback,
-        isFlag: true, negatable: negatable);
+        isFlag: true, negatable: negatable, hide: hide);
   }
 
   /**
    * Defines a value-taking option. Throws an [ArgumentError] if:
    *
    * * There is already an option with name [name].
    * * There is already an option using abbreviation [abbr].
    */
   void addOption(String name, {String abbr, String help, List<String> allowed,
       Map<String, String> allowedHelp, String defaultsTo,
@@ skipping 109 matching lines @@
           'Could not find an option named "$name".');
     }
 
     return _options[name];
   }
 
   /** Get the names of the options as an [Iterable]. */
   Iterable<String> get options => _options.keys;
 }