ASSERT_EQ(TF_OK, TF_GetCode(s_)) << TF_Message(s_);

  // Delete the gradient func.
  // It is safe to delete after adding a copy to host graph.
  TF_DeleteFunction(grad_func);

  // Check that GraphDef did not change
  GraphDef gdef2;
  GetGraphDef(host_graph_, &gdef2);
  ASSERT_EQ(gdef.DebugString(), gdef2.DebugString());

  // Use and run func
  TF_Operation* func_feed = Placeholder(host_graph_, s_);

    TF_ImportGraphDefResults* results, int* num_opers, TF_Operation*** opers);

// Fetches any input mappings requested via
// TF_ImportGraphDefOptionsAddInputMapping() that didn't appear in the GraphDef
// and weren't used as input to any node in the imported graph def. The number
// of fetched mappings is returned in `num_missing_unused_input_mappings`. The