code: def _max_pooling_2d(x):
      return max_pooling_2d(x, ksize=2)
  
file_path: chainercv/chainercv/links/model/vgg/vgg16.py
imports: from __future__ import division
  import numpy
  import chainer
  from chainer.functions import dropout
  from chainer.functions import max_pooling_2d
  from chainer.functions import relu
  from chainer.functions import softmax
  from chainer.initializers import constant
  from chainer.initializers import normal
  from chainer.links import Linear
  from chainercv.links.connection.conv_2d_activ import Conv2DActiv
  from chainercv.links.model.pickable_sequential_chain import PickableSequentialChain
  from chainercv import utils
label_desc: Use image node_id 1 for calling a global function with example usage: _max_pooling_2d(x) and returns: max_pooling_2d