Method _updateStackingOrder

src/cdk/overlay/overlay-ref.ts:497–501

* Updates the stacking order of the element, moving it to the top if necessary. * This is required in cases where one overlay was detached, while another one, * that should be behind it, was destroyed. The next time both of them are opened, * the stacking will be wrong, because the detached

()

   * in its original DOM position.
   */
  private _updateStackingOrder() {
    if (!this._config.usePopover && this._host.nextSibling) {
      this._host.parentNode!.appendChild(this._host);
    }
  }

  /** Detaches the backdrop (if any) associated with the overlay. */
  detachBackdrop(): void {