// result of TF_ImportGraphDefOptionsNumReturnOutputs()).  If
// `num_return_outputs` is non-zero, `return_outputs` must be of length
// `num_return_outputs`. Otherwise it can be null.
TF_CAPI_EXPORT extern void TF_GraphImportGraphDefWithReturnOutputs(
    TF_Graph* graph, const TF_Buffer* graph_def,
    const TF_ImportGraphDefOptions* options, TF_Output* return_outputs,
    int num_return_outputs, TF_Status* status);

  TF_ImportGraphDefOptionsAddReturnOutput(opts, "scalar", 0);
  EXPECT_EQ(2, TF_ImportGraphDefOptionsNumReturnOutputs(opts));
  TF_Output return_outputs[2];
  TF_GraphImportGraphDefWithReturnOutputs(graph, graph_def, opts,
                                          return_outputs, 2, s);
  ASSERT_EQ(TF_OK, TF_GetCode(s)) << TF_Message(s);

  TF_Operation* scalar = TF_GraphOperationByName(graph, "scalar");