code: def query(self, question):
      u = self.encoder(self.B, question)
      for memory in self.memories:
          u = memory.query(u)
      a = self.W(u)
      return a
  
imports: import collections
  import json
  import os
  import numpy
  import six
  import chainer
  from chainer import backend
  import chainer.functions
  from chainer import initializers
  import chainer.links
  import babi
label_desc: Use image node_id 4 for calling the MemNN obj's underlying member method code with example usage: obj.query(question) and returns: a