code: function someProperties(map, predicate) {
          for (var key in map) {
              if (!predicate || predicate(map[key], key))
                  return true;
          }
          return false;
      }
docs: Returns true if a Map<T> has some matching property.
  
  @param map A map whose properties should be tested.
  @param predicate An optional callback used to test each property.