'_collapsedChanged',
          },

          /**
           * Unique anchor ID for deep-linking.
           */
          anchorId: {
            type: String,
            reflectToAttribute: true,
          },

          _paramText: String,
        },

        listeners: {
          'transitionEnd':       '_onTransitionEnd',
          'webkitTransitionEnd': '_onTransitionEnd',
        },

        ready: function() {
          this._isReady = true;
        },

        /**
         * Resets any state that was