code: def __init__(self):
      self.n_call = 0
  
imports: from __future__ import division
  import copy
  import unittest
  import numpy
  import six
  from chainer import iterators
  from chainer import serializers
  from chainer import testing
label_desc: Use image node_id 1 to create a new InvalidOrderSampler object from inherited base classes: object with example: obj = InvalidOrderSampler()