code: def size(self):
      return self.next_id
  
imports: import copy
  import numpy
  import six
  import chainer
  from chainer.backends import cuda
  from chainer import device_resident
  from chainer import function
  from chainer.initializers import uniform
  from chainer import link
  from chainer import utils
  from chainer.utils import type_check
  from chainer import variable
label_desc: Use image node_id 2 for calling the TreeParser obj's underlying member method code with example usage: obj.size() and returns: self