Method _getExpansionModel

src/cdk/tree/tree.ts:363–369

()

  }

  _getExpansionModel() {
    if (!this.treeControl) {
      this._expansionModel ??= new SelectionModel<K>(true);
      return this._expansionModel;
    }
    return this.treeControl.expansionModel;
  }

  /** Set up a subscription for the data provided by the data source. */
  private _subscribeToDataChanges() {