Method role

src/cdk/tree/tree.ts:1211–1213

()

   * @breaking-change 21.0.0
   */
  @Input() get role(): 'treeitem' | 'group' {
    return 'treeitem';
  }

  set role(_role: 'treeitem' | 'group') {
    // ignore any role setting, we handle this internally.