this.shortcuts.on("Return", event => {
   if (!this.tooltip.isVisible()) {
     return;
   }
   this.commit();
   this.hide();
   event.stopPropagation();
   event.preventDefault();
 });
 /**
   * Reports if the tooltip is currently shown
   *
   * @return {Boolean} True if the tooltip is displayed.
   */
  isVisible() {
    return this.tooltip.isVisible();
  }