import tensorflow as tf

      # Adds a set of collections.
      tf.add_to_collection("int_collection", 3)
      tf.add_to_collection("float_collection", 3.5)
      tf.add_to_collection("string_collection", "hello")
      tf.add_to_collection("variable_collection", v0)
      # Add QueueRunners.
      tf.train.add_queue_runner(qr)
      # Adds user_defined proto in three formats: string, bytes and Any.
      queue_runner = queue_runner_pb2.QueueRunnerDef(queue_name="test_queue")
      tf.add_to_collection("user_defined_string_collection", str(queue_runner))
      tf.add_to_collection("user_defined_bytes_collection",
                           queue_runner.SerializeToString())
