Method _getSetSize

src/cdk/tree/tree.ts:1373–1375

* Determines the size of this node's parent's child set. * * This is intended to be used for `aria-setsize`.

()

   * This is intended to be used for `aria-setsize`.
   */
  _getSetSize(): number {
    return this._tree._getSetSize(this._data);
  }

  /**
   * Determines the index (starting from 1) of this node in its parent's child set.