TF_AddInputList(desc, inputs, 2);
  return TF_FinishOperation(desc, s);
}

void NegHelper(TF_Operation* n, TF_Graph* graph, TF_Status* s, const char* name,
               TF_Operation** op) {
  TF_OperationDescription* desc = TF_NewOperation(graph, "Neg", name);
  TF_Output neg_input = {n, 0};
  TF_AddInput(desc, neg_input);
  *op = TF_FinishOperation(desc, s);
  ASSERT_EQ(TF_OK, TF_GetCode(s)) << TF_Message(s);

  TF_Status* status = TF_NewStatus();
  TF_Operation* arg = TF_FinishOperation(arg_descr, status);
  ASSERT_TRUE(TF_GetCode(status) == TF_OK) << TF_Message(status);
  TF_OperationDescription* id_descr =
      TF_NewOperation(function_graph, "Identity", "id");
  TF_SetAttrType(id_descr, "T", TF_INT32);
  TF_AddInput(id_descr, {arg, 0});
  TF_Operation* id = TF_FinishOperation(id_descr, status);

  TF_OperationDescription* placeholder_desc =
      TF_NewOperation(body.get(), "Placeholder", "Placeholder");
  TF_SetAttrType(placeholder_desc, "dtype", TF_FLOAT);
  TF_Operation* placeholder_op = TF_FinishOperation(placeholder_desc, status);
  if (TF_GetCode(status) != TF_OK) return;
  TF_Output x{placeholder_op, 0};

  TF_OperationDescription* reduce_desc =

    auto* tf_opdesc = op_.release();
    if (tf_opdesc == nullptr) {
      return errors::InvalidArgument("AbstractOp is incomplete.");
    }
    TF_Status* s = TF_NewStatus();
    auto* operation = TF_FinishOperation(tf_opdesc, s);
    TF_RETURN_IF_ERROR(StatusFromTF_Status(s));
    TF_DeleteStatus(s);
    *num_retvals = TF_OperationNumOutputs(operation);
    for (int i = 0; i < *num_retvals; ++i) {