new_contents: # Tai Sakuma <tai.sakuma@gmail.com>
  from __future__ import print_function
  import sys
  import copy
  import pytest
  
  try:
      import unittest.mock as mock
  except ImportError:
      import mock
  
  import alphatwirl
  
  class A(object):
      def __init__(self, a):
          pass
  
  class B(object):
      def __init__(self):
          self._repr = 'B'
  
      def __repr__(self):
          return self._repr
  
  ## In Python 2 with mock 2.0.0, mock.Mock with spec sometimes cannot
  ## be copied or deep-copied.
  ## The tests in this file demonstrate.
  
  ##__________________________________________________________________||
  @pytest.mark.skipif(sys.version_info < (3, 0), reason='require python 3')
  def test_copy_a():
      obj = mock.Mock(spec=A)
      copy.deepcopy(obj) # doesn't work in python 2 with mock 2.0.0
  
  @pytest.mark.skipif(sys.version_info < (3, 0), reason='require python 3')
  def test_copy_b():
      obj = mock.Mock(spec=B)
      obj_copy = copy.copy(obj)
      repr(obj_copy) # doesn't work in python 2 with mock 2.0.0
  
  ##__________________________________________________________________||
  
  
subject: add tests/unit/examples/test_mock.py