@Override
  public IdConverter getIdConverter() {
    return null;
  }
Does nothing. Simply indicates success immediately.
@param blobId (ignored).
@param serviceId (ignored).
@param callback the {@link Callback} to invoke on operation completion.
@return a {@link FutureResult} that will eventually contain the result of the operation.
ambry-tools/src/main/java/com/github/ambry/tools/perf/rest/PerfRouter.java