private function dumpStructure() {
    dump("Requesters:");
    dump($this->requesters);

    dump("Request roots:");
    dump($this->requestRoots);

    dump("Request paths:");
    dump($this->requestPaths);

    dump("Local names:");
    dump($this->localNames);

    if (isset($this->tree)) {
      dump("Containment tree:");
      dump($this->tree);
    }
  }