// We assume that any tensors already placed on this device are
      // ParallelTensors.
      typed_inputs.emplace_back(reinterpret_cast<ParallelTensor*>(
          TFE_TensorHandleDevicePointer(input, status)));
      if (TF_GetCode(status) != TF_OK) return;
    } else {
      typed_inputs.emplace_back(input);
    }
  }

  absl::optional<std::vector<MaybeParallelTensorOwned>> maybe_typed_outputs(

    return;
  }
  unwrapped_results.resize(real_num_outputs);
  outputs->reserve(real_num_outputs);
  for (TFE_TensorHandle* unwrapped_result : unwrapped_results) {
    outputs->emplace_back(unwrapped_result);
  }
}

ParallelDevice::ParallelDevice(const std::vector<std::string>& devices,
                               bool is_async, int in_flight_nodes_limit)
    : underlying_devices_(devices),

  std::vector<TFE_TensorHandle*> tensors() const {
    std::vector<TFE_TensorHandle*> result;
    result.reserve(tensors_.size());
    for (const TensorHandlePtr& tensor : tensors_) {
      result.emplace_back(tensor.get());
    }
    return result;
  }

 private:
  ParallelTensor(const ParallelDevice& device,
                 std::vector<TensorHandlePtr> tensors,