ProtoUtil { public static RpcRequestHeaderProto makeRpcRequestHeader(RPC.RpcKind rpcKind, RpcRequestHeaderProto.OperationProto operation, int callId, int retryCount, byte[] uuid) { return makeRpcRequestHeader(rpcKind, operation, callId, retryCount, uuid, null); }  static int readRawVarint32(DataInput in); static IpcConnectionContextProto makeIpcConnectionContext(
      final String protocol,
      final UserGroupInformation ugi, final AuthMethod authMethod); static UserGroupInformation getUgi(IpcConnectionContextProto context); static UserGroupInformation getUgi(UserInformationProto userInfo); static RPC.RpcKind convert( RpcKindProto kind); static RpcRequestHeaderProto makeRpcRequestHeader(RPC.RpcKind rpcKind,
      RpcRequestHeaderProto.OperationProto operation, int callId,
      int retryCount, byte[] uuid); static RpcRequestHeaderProto makeRpcRequestHeader(RPC.RpcKind rpcKind,
      RpcRequestHeaderProto.OperationProto operation, int callId,
      int retryCount, byte[] uuid, AlignmentContext alignmentContext);  }
@Test public void testRpcClientId() { byte[] uuid = ClientId.getClientId(); RpcRequestHeaderProto header = ProtoUtil.makeRpcRequestHeader( RpcKind.RPC_PROTOCOL_BUFFER, OperationProto.RPC_FINAL_PACKET, 0, RpcConstants.INVALID_RETRY_COUNT, uuid); assertTrue(Arrays.equals(uuid, header.getClientId().toByteArray())); }