all compiler warnings in a file, etc.)
*   Tests should follow the
    [testing best practices](https://www.tensorflow.org/community/contribute/tests)
    guide.

#### License

Include a license at the top of new files.

*   [C/C++ license example](https://github.com/tensorflow/tensorflow/blob/master/tensorflow/core/framework/op.cc#L1)

    absl::Span<const tensorflow::DataType> dtypes) {
  if (call_state_.top().backward_tape != nullptr) {
    // If we're forwarding Accumulate calls to backward_tape's RecordOperation,
    // we should also delegate ShouldRecord.
    return call_state_.top().backward_tape->ShouldRecord(tensor_ids, dtypes);
  }
  if (call_state_.top().accumulating) {
    return false;
  }
  for (int i = 0; i < tensor_ids.size(); ++i) {

  // Returns whether the runtime is backed by TFRT or the legacy TF Eager
  // Runtime. This is necessary to decouple runtime-dependent
  // code that is layered on top of the runtime.
  virtual bool UsesTFRT() = 0;

  // List attributes of available devices
  virtual void ListDevices(std::vector<DeviceAttributes>* devices) = 0;