code: def __anext__(self):
      return self.q.get()
  
imports: from __future__ import absolute_import, division, print_function
  import collections
  import heapq
  from tornado import gen, ioloop
  from tornado.concurrent import Future
  from tornado.locks import Event
label_desc: Use image node_id 2 for calling the _QueueIterator obj's underlying member method code with example usage: obj.__anext__() and returns: self