text: """
  Scheduler queues
  """
  
  import marshal, cPickle as pickle
  
  from queuelib import queue
  
  def _serializable_queue(queue_class, serialize, deserialize):
  
      class SerializableQueue(queue_class):
  
          def push(self, obj):
              s = serialize(obj)
              super(SerializableQueue, self).push(s)
  
          def pop(self):
              s = super(SerializableQueue, self).pop()
              if s:
                  return deserialize(s)
  
      return SerializableQueue
  
  def _pickle_serialize(obj):
      try:
          return pickle.dumps(obj, protocol=2)
      except pickle.PicklingError as e:
          raise ValueError(str(e))
  
  PickleFifoDiskQueue = _serializable_queue(queue.FifoDiskQueue, \
      _pickle_serialize, pickle.loads)
  PickleLifoDiskQueue = _serializable_queue(queue.LifoDiskQueue, \
      _pickle_serialize, pickle.loads)
  MarshalFifoDiskQueue = _serializable_queue(queue.FifoDiskQueue, \
      marshal.dumps, marshal.loads)
  MarshalLifoDiskQueue = _serializable_queue(queue.LifoDiskQueue, \
      marshal.dumps, marshal.loads)
  FifoMemoryQueue = queue.FifoMemoryQueue
  LifoMemoryQueue = queue.LifoMemoryQueue
  