Method _getShadowRoot

src/cdk/drag-drop/drag-ref.ts:1561–1567

* Lazily resolves and returns the shadow root of the element. We do this in a function, rather * than saving it in property directly on init, because we want to resolve it as late as possible * in order to ensure that the element has been moved into the shadow DOM. Doing it inside the * con

()

   * constructor might be too early if the element is inside of something like `ngFor` or `ngIf`.
   */
  private _getShadowRoot(): ShadowRoot | null {
    if (this._cachedShadowRoot === undefined) {
      this._cachedShadowRoot = _getShadowRoot(this._rootElement);
    }

    return this._cachedShadowRoot;
  }

  /** Gets the element into which the drag preview should be inserted. */
  private _getPreviewInsertionPoint(