old_contents: import pickle
  from six.moves import range
  
  from fuel.utils import do_not_pickle_attributes
  
  
  @do_not_pickle_attributes("non_pickable", "bulky_attr")
  class TestClass(object):
      def __init__(self):
          self.load()
  
      def load(self):
          self.bulky_attr = list(range(100))
          self.non_pickable = lambda x: x
  
  
  def test_do_not_pickle_attributes():
      cl = TestClass()
  
      dump = pickle.dumps(cl)
  
      loaded = pickle.loads(dump)
      assert loaded.bulky_attr == list(range(100))
      assert loaded.non_pickable is not None
  
new_contents: import pickle
  from six.moves import range
  
  from fuel.utils import do_not_pickle_attributes, expand_axis_label
  
  
  @do_not_pickle_attributes("non_pickable", "bulky_attr")
  class TestClass(object):
      def __init__(self):
          self.load()
  
      def load(self):
          self.bulky_attr = list(range(100))
          self.non_pickable = lambda x: x
  
  
  def test_do_not_pickle_attributes():
      cl = TestClass()
  
      dump = pickle.dumps(cl)
  
      loaded = pickle.loads(dump)
      assert loaded.bulky_attr == list(range(100))
      assert loaded.non_pickable is not None
  
  
  def test_expand_axis_label():
      assert expand_axis_label('b') == 'batch'
      assert expand_axis_label('c') == 'channel'
      assert expand_axis_label('t') == 'time'
      assert expand_axis_label('0') == 'axis_0'
      assert expand_axis_label('1') == 'axis_1'
      assert expand_axis_label('0b') == '0b'
      assert expand_axis_label('') == ''
  
subject: Add unit test for expand_axis_label