@Override
  public Future<Void> undeleteBlob(String blobId, String serviceId, Callback<Void> callback,
      QuotaChargeCallback quotaChargeCallback) {
    logger.trace("Received undeleteBlob call");
    FutureResult<Void> futureResult = new FutureResult<Void>();
    if (!routerOpen) {
      completeOperation(futureResult, callback, null, ROUTER_CLOSED_EXCEPTION);
    } else {
      completeOperation(futureResult, callback, null, null);
    }
    return futureResult;
  }
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