Method constructor

src/cdk/tree/tree-with-tree-control.spec.ts:1294–1299

(public treeControl: TreeControl<TestData>)

  }

  constructor(public treeControl: TreeControl<TestData>) {
    super();
    for (let i = 0; i < 3; i++) {
      this.addData();
    }
  }

  connect(collectionViewer: CollectionViewer): Observable<TestData[]> {
    this.isConnected = true;