docs: function (evt) {
                  var state = ariaUtilsJson.copy(evt.state), title;
                  if (state && state.__info) {
                      title = state.__info.title;
                      delete state.__info;
                  } else {
                      var stateInfo = this._retrieveFromMemory();
                      title = stateInfo ? stateInfo.state.title : null;
                  }
                  this.state = state;
                  if (title) {
                      this._setTitle(title);
                  }
                  this.$raiseEvent({
                      name : "popstate",
                      state : state
                  });
              }