makeTabbable(elem = this.items[0]) {
    const isTabbable = this.tabbable;
    this.items.forEach((item) => {
      const nonTabbableTargetIndex = elem.isEqualNode(item) ? 0 : -1;
      item.tabIndex = isTabbable ? 0 : nonTabbableTargetIndex;
    });
  }
/**
   * @private
   * @param {HTMLElement} elem an element residing within the toolbar that can accept
   */
@private
@param {HTMLElement} elem an element residing within the toolbar that can accept
@private @param { HTMLElement } elem an element residing within the toolbar that can accept
makeTabbable(elem = this.items[0]) {
    const isTabbable = this.tabbable;
    this.items.forEach((item) => {
      const nonTabbableTargetIndex = elem.isEqualNode(item) ? 0 : -1;
      item.tabIndex = isTabbable ? 0 : nonTabbableTargetIndex;
    });
  }
makeTabbable ( elem = this . items [ 0 ] ) { const isTabbable = this . tabbable ; this . items . forEach ( ( item ) => { const nonTabbableTargetIndex = elem . isEqualNode ( item ) ? 0 : - 1 ; item . tabIndex = isTabbable ? 0 : nonTabbableTargetIndex ; } ) ; }
@private
 @param {HTMLElement} elem an element residing within the toolbar that can accept
@private @param { HTMLElement } elem an element residing within the toolbar that can accept