@Override
  public void close() {
    isOpen = false;
    if (idConverter != null) {
      try {
        idConverter.close();
      } catch (IOException e) {
        throw new RuntimeException(e);
      }
    }
  }
Enumerates the different operation types in the router.
ambry-frontend/src/test/java/com/github/ambry/frontend/FrontendRestRequestServiceTest.java