         // children in an idiomatic way.
            // We poke this property in case the element has changed. This will
            // cause the focus target for the `iron-dropdown` to be updated as
            // necessary:
            this._dropdownContent = this.contentElement;
            this.fire('paper-dropdown-open');
          } else if (oldOpened != null) {
            this.fire('paper-dropdown-close');
          }
        },

        /**
         * If the dropdown is open when disabled becomes 