Method traverse

packages/react-aria/src/focus/FocusScope.tsx:1079–1088

(node: TreeNode = this.root)

  // Pre Order Depth First
  *traverse(node: TreeNode = this.root): Generator<TreeNode> {
    if (node.scopeRef != null) {
      yield node;
    }
    if (node.children.size > 0) {
      for (let child of node.children) {
        yield* this.traverse(child);
      }
    }
  }

  clone(): Tree {
    let newTree = new Tree();