GraphDef graph_def;
  TF_EXPECT_OK(root.ToGraphDef(&graph_def));
  return graph_def;
}

QueueRunnerDef BuildQueueRunnerDef(
    const std::string& queue_name, const std::vector<std::string>& enqueue_ops,
    const std::string& close_op, const std::string& cancel_op,
    const std::vector<Code>& queue_closed_error_codes) {
  QueueRunnerDef queue_runner_def;
  *queue_runner_def.mutable_queue_name() = queue_name;

  // TODO(yuefengz): we may want to initialize from queues and ops in the
  // future.
  static Status New(const QueueRunnerDef& queue_runner_def,
                    std::unique_ptr<QueueRunner>* result);

  /// Creates a new QueueRunner with a coordinator, see coordinator.h for usage.
  static Status New(const QueueRunnerDef& queue_runner_def, Coordinator* coord,
                    std::unique_ptr<QueueRunner>* result);

#include "tensorflow/core/platform/env.h"

namespace tensorflow {

Status QueueRunner::New(const QueueRunnerDef& queue_runner_def,
                        std::unique_ptr<QueueRunner>* result) {
  result->reset(new QueueRunner());
  return (*result)->Init(queue_runner_def);
}

Status QueueRunner::New(const QueueRunnerDef& queue_runner_def,
                        Coordinator* coord,