code: function (evt) {
              if (evt.name == "environmentChanged") {
                  if (this._urlService) {
                      this._urlService.$dispose();
                      this._urlService = null;
                  }
  
                  if (this._requestHandler) {
                      this._requestHandler.$dispose();
                      this._requestHandler = null;
                  }
                  return;
              }
          }
docs: Listener for the event environmentChanged raised by any environment container
  (aria.core.environment.Environment)
  @private
  @param {Object} evt Event