string s1, s2;
  tensorflow::FunctionDef fdef1, fdef2;
  ASSERT_TRUE(GetFunctionDef(f1, &fdef1));
  ASSERT_TRUE(GetFunctionDef(f2, &fdef2));
  SerializeToStringDeterministic(fdef1, &s1);
  SerializeToStringDeterministic(fdef2, &s2);
  ASSERT_EQ(s1, s2);
}

string GetName(TF_Function* func) {
  tensorflow::FunctionDef fdef;
  GetFunctionDef(func, &fdef);
  return fdef.signature().name();
}

bool IsNeg(const tensorflow::NodeDef& node_def, const string& input);

bool GetGraphDef(TF_Graph* graph, tensorflow::GraphDef* graph_def);

bool GetNodeDef(TF_Operation* oper, tensorflow::NodeDef* node_def);

bool GetFunctionDef(TF_Function* func, tensorflow::FunctionDef* func_def);

bool GetAttrValue(TF_Operation* oper, const char* attr_name,
                  tensorflow::AttrValue* attr_value, TF_Status* s);

  EXPECT_EQ(TF_OK, TF_GetCode(s)) << TF_Message(s);
  if (ret) ret = node_def->ParseFromArray(buffer->data, buffer->length);
  TF_DeleteBuffer(buffer);
  TF_DeleteStatus(s);
  return ret;
}

bool GetFunctionDef(TF_Function* func, tensorflow::FunctionDef* func_def) {
  TF_Status* s = TF_NewStatus();
  TF_Buffer* buffer = TF_NewBuffer();
  TF_FunctionToFunctionDef(func, buffer, s);
  bool ret = TF_GetCode(s) == TF_OK;