return absl::OkStatus();
}

// Tracks monotonic sequence numbers for graphs.
class ClusterSequenceNumberGenerator {
 public:
  void Reset() {
    mutex_lock lock(mu_);
    sequence_numbers_.clear();
  }

  int64 GetNext(uint64 key) {
    mutex_lock lock(mu_);
    return sequence_numbers_[key]++;
  }

  static ClusterSequenceNumberGenerator& Global() {
    static ClusterSequenceNumberGenerator* gen =

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

  TF_DeleteFunction(grad_func);

  const StackTracesMap* func_stack_traces;
  const StackTracesMap* grad_stack_traces;

  {
    mutex_lock l(host_graph_->mu);
    auto flib_def = host_graph_->graph.flib_def();
    func_stack_traces = flib_def.GetStackTraces(func_name_);
    grad_stack_traces = flib_def.GetStackTraces("MyGrad");
  }

  GTEST_DISALLOW_COPY_AND_ASSIGN_(ThreadWithParam);
};

// MutexBase and Mutex implement mutex on pthreads-based platforms. They
// are used in conjunction with class MutexLock:
//
//   Mutex mutex;
//   ...
//   MutexLock lock(&mutex);  // Acquires the mutex and releases it at the end
//                            // of the current scope.
//
// MutexBase implements behavior for both statically and dynamically

  GTEST_DISALLOW_COPY_AND_ASSIGN_(ThreadWithParam);
};

// MutexBase and Mutex implement mutex on pthreads-based platforms. They
// are used in conjunction with class MutexLock:
//
//   Mutex mutex;
//   ...
//   MutexLock lock(&mutex);  // Acquires the mutex and releases it at the end
//                            // of the current scope.
//
// MutexBase implements behavior for both statically and dynamically