TF_ImportGraphDefOptionsSetPrefix(opts, "imported");
  TF_GraphImportGraphDef(graph, graph_def, opts, s);
  ASSERT_EQ(TF_OK, TF_GetCode(s)) << TF_Message(s);

  TF_Operation* scalar = TF_GraphOperationByName(graph, "imported/scalar");
  TF_Operation* feed = TF_GraphOperationByName(graph, "imported/feed");
  TF_Operation* neg = TF_GraphOperationByName(graph, "imported/neg");
  ASSERT_TRUE(scalar != nullptr);