TF_Buffer* op_list_buf = TF_GetAllOpList();
  TF_Status* status = TF_NewStatus();
  auto* api_def_map = TF_NewApiDefMap(op_list_buf, status);
  EXPECT_EQ(TF_OK, TF_GetCode(status)) << TF_Message(status);
  TF_DeleteStatus(status);

  string op_name = "TestCApi";
  status = TF_NewStatus();
  auto* api_def_buf =
      TF_ApiDefMapGet(api_def_map, op_name.c_str(), op_name.size(), status);

  using Base::pair;

  string ToString() const { return strings::StrCat(first, "->", second); }
};

class CApiFunctionTest : public ::testing::Test {
 protected:
  CApiFunctionTest()
      : s_(TF_NewStatus()),
        func_graph_(TF_NewGraph()),
        host_graph_(TF_NewGraph()),
        func_(nullptr) {}

  void SetUp() override {}

  ~CApiFunctionTest() override {
    TF_DeleteFunction(func_);