code: function getOwnKeys(map) {
          var keys = [];
          for (var key in map)
              if (hasOwnProperty.call(map, key)) {
                  keys.push(key);
              }
          return keys;
      }
docs: Gets the owned, enumerable property keys of a map-like.
  
  NOTE: This is intended for use with MapLike<T> objects. For Map<T> objects, use
  Object.keys instead as it offers better performance.
  
  @param map A map-like.