Adding isNotEmpty property to collection and string.

sdk/lib/collection/maps.dart

 // Copyright (c) 2012, 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.
 
 part of dart.collection;
 
 /*
  * Helper class which implements complex [Map] operations
  * in term of basic ones ([Map.keys], [Map.operator []],
  * [Map.operator []=] and [Map.remove].)  Not all methods are
@@ skipping 40 matching lines @@
   }
 
   static Iterable getValues(Map map) {
     return map.keys.map((key) => map[key]);
   }
 
   static int length(Map map) => map.keys.length;
 
   static bool isEmpty(Map map) => map.keys.isEmpty;
 
+  static bool isNotEmpty(Map map) => map.keys.isNotEmpty;
+
   /**
    * Returns a string representing the specified map. The returned string
    * looks like this: [:'{key0: value0, key1: value1, ... keyN: valueN}':].
    * The value returned by its [toString] method is used to represent each
    * key or value.
    *
    * If the map collection contains a reference to itself, either
    * directly as a key or value, or indirectly through other collections
    * or maps, the contained reference is rendered as [:'{...}':]. This
    * prevents the infinite regress that would otherwise occur. So, for example,
    * calling this method on a map whose sole entry maps the string key 'me'
    * to a reference to the map would return [:'{me: {...}}':].
    *
    * A typical implementation of a map's [toString] method will
    * simply return the results of this method applied to the collection.
    */
   static String mapToString(Map m) => ToString.mapToString(m);
 }