TF_OperationDescription* desc = TF_NewOperation(graph, "AddN", name);
  TF_Output inputs[2] = {l, r};
  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};