wrapNodesInNewRootNode(nodes) {
    const children = [...nodes];
    return {
      name: this.documentUrl.toString(),
      resourceBytes: children.reduce((acc, cur) => cur.resourceBytes + acc, 0),
      encodedBytes: children.reduce((acc, cur) => (cur.encodedBytes ?? 0) + acc, 0),
      unusedBytes: children.reduce((acc, cur) => (cur.unusedBytes || 0) + acc, 0),
      children,
    };
  }
@param {LH.Treemap.Node[]} nodes
@return {LH.Treemap.Node}