Method level

src/cdk/tree/tree.ts:1335–1340

()

  }

  get level(): number {
    // If the tree has a levelAccessor, use it to get the level. Otherwise read the
    // aria-level off the parent node and use it as the level for this node (note aria-level is
    // 1-indexed, while this property is 0-indexed, so we don't need to increment).
    return this._tree._getLevel(this._data) ?? this._parentNodeAriaLevel;
  }

  /** Determines if the tree node is expandable. */
  _isExpandable(): boolean {