//      output tensor naming, but it the index is actually an input index)
struct EdgeSpec : public std::pair<string, string> {
  typedef std::pair<string, string> Base;

  // Inherit the set of constructors
  using Base::pair;

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

class CApiFunctionTest : public ::testing::Test {
 protected:
  CApiFunctionTest()

  EXPECT_EQ(TF_STRING, TF_TensorType(t_out));
  EXPECT_EQ(0, TF_NumDims(t_out));
  ASSERT_EQ(TF_TensorByteSize(t_in.get()), TF_TensorByteSize(t_out));
  TF_TString* t_in_tstr = static_cast<TF_TString*>(TF_TensorData(t_in.get()));
  TF_TString* t_out_tstr = static_cast<TF_TString*>(TF_TensorData(t_out));
  EXPECT_EQ(absl::string_view(test_string),
            absl::string_view(TF_TString_GetDataPointer(t_out_tstr),

    const char* dev = TF_DeviceListName(devices, i, status.get());
    ASSERT_EQ(TF_OK, TF_GetCode(status.get())) << TF_Message(status.get());
    string device_name(dev);
    if (device_name.find("GPU:0") != string::npos) {
      has_gpu0 = true;
    }
    if (device_name.find("GPU:1") != string::npos) {
      has_gpu1 = true;
    }
  }

  const char* kCPUDevice = "CPU:0";
  if (!has_gpu0 || !has_gpu1) {