@Override
  public String toString() {
    return "AdminRequest[ClientId=" + clientId + ", CorrelationId=" + correlationId + ", Type=" + type
        + ", PartitionId=" + partitionId + "]";
  }
@return the {@link PartitionId} that the operation will work on. {@link null} if not applicable.
ambry-protocol/src/main/java/com/github/ambry/protocol/AdminRequest.java