Method closeSubMenuOf

src/cdk/menu/menu-stack.ts:149–158

* Pop items off of the stack up to but excluding `lastItem` and emit each on the close * observable. If the stack is empty or `lastItem` is not on the stack it does nothing. * @param lastItem the element which should be left on the stack * @return whether or not an item was removed from the

(lastItem: MenuStackItem)

   * @return whether or not an item was removed from the stack
   */
  closeSubMenuOf(lastItem: MenuStackItem) {
    let removed = false;
    if (this._elements.indexOf(lastItem) >= 0) {
      removed = this.peek() !== lastItem;
      while (this.peek() !== lastItem) {
        this._close.next({item: this._elements.pop()!});
      }
    }
    return removed;
  }

  /**
   * Pop off all MenuStackItems and emit each one on the `close` observable one by one.