@Override
  public long sizeInBytes() {
    return sizeInBytes;
  }
Constructs an admin request with the given parameters.
@param type the type of the request.
@param partitionId the {@link PartitionId} that the operation should work on. {@link null} if not applicable.
@param correlationId an ID to help match responses to requests.
@param clientId the ID of the client.
ambry-protocol/src/main/java/com/github/ambry/protocol/AdminRequest.java