SavedModelReadCount("2").IncrementBy(1);
  EXPECT_EQ(SavedModelReadCount("2").value(), 2);
}

TEST(MetricsTest, TestCheckpointRead) {
  EXPECT_EQ(CheckpointReadDuration("foo").value().num(), 0);
  CheckpointReadDuration("foo").Add(100);
  EXPECT_EQ(CheckpointReadDuration("foo").value().num(), 1);
}

TEST(MetricsTest, TestCheckpointWrite) {
  EXPECT_EQ(CheckpointWriteDuration("foo").value().num(), 0);

monitoring::GaugeCell<std::string>& SavedModelFoundFingerprintOnLoad();

// Returns "/tensorflow/core/checkpoint/read/read_durations" cell belonging to
// field `api_label`.
monitoring::SamplerCell& CheckpointReadDuration(absl::string_view api_label);

// Returns "/tensorflow/core/checkpoint/write/write_durations" cell belonging to
// field `api_label`.
monitoring::SamplerCell& CheckpointWriteDuration(absl::string_view api_label);

}

monitoring::GaugeCell<std::string>& SavedModelFoundFingerprintOnLoad() {
  return *saved_model_found_fingerprint_on_load->GetCell();
}

monitoring::SamplerCell& CheckpointReadDuration(absl::string_view api_label) {
  return *checkpoint_read_durations->GetCell(std::string(api_label));
}

monitoring::SamplerCell& CheckpointWriteDuration(absl::string_view api_label) {