old_contents: from pymonet.maybe import Maybe
  from pymonet.utils import increase
  
  def wrong_mapper(value):
      assert True is False
  
  
  def test_maybe_eq_operator_shuld_compare_values():
  
      assert Maybe.just(42) == Maybe.just(42)
      assert Maybe.just(None) == Maybe.just(None)
  
      assert Maybe.just(42) != Maybe.nothing()
  
  
  def test_maybe_map_operator_should_be_applied_only_on_just_value():
      assert Maybe.just(42).map(increase) == Maybe.just(43)
      assert Maybe.nothing().map(increase) == Maybe.nothing()
  
  
  def test_maybe_map_should_not_call_mapper_when_monad_has_nothing():
      Maybe.nothing().map(wrong_mapper)
  
  
  def test_maybe_fold_should_retrun_result_of_mapper_called_with_maybe_value():
      assert Maybe.just(42).fold(increase) == 43
  
  
  def test_maybe_fold_should_not_call_mapper_when_monad_has_nothing():
      Maybe.nothing().fold(wrong_mapper)
  
  
  def test_maybe_get_or_else_method_should_return_maybe_value_when_monad_is_not_empy():
      assert Maybe.just(42).get_or_else(0) == 42
  
  
  def test_maybe_get_or_else_method_should_return_argument_when_monad_is_empy():
      assert Maybe.nothing().get_or_else(0) == 0
  
  
  def test_maybe_is_nothing_should_return_proper_boolean():
      assert Maybe.just(42).is_nothing is False
      assert Maybe.nothing().is_nothing is True
  
  
  def test_maybe_if_filter_returns_false_method_should_return_empty_maybe():
      assert Maybe.just(41).filter(lambda value: value % 2 == 0) == Maybe.nothing()
  
  
  def test_maybe_if_filter_returns_true_method_should_return_self():
      assert Maybe.just(42).filter(lambda value: value % 2 == 0) == Maybe.just(42)
  
new_contents: from pymonet.maybe import Maybe
  from pymonet.utils import increase
  
  
  def wrong_mapper(_):
      assert True is False
  
  
  def test_maybe_eq_operator_shuld_compare_values():
  
      assert Maybe.just(42) == Maybe.just(42)
      assert Maybe.just(None) == Maybe.just(None)
  
      assert Maybe.just(42) != Maybe.nothing()
  
  
  def test_maybe_map_operator_should_be_applied_only_on_just_value():
      assert Maybe.just(42).map(increase) == Maybe.just(43)
      assert Maybe.nothing().map(increase) == Maybe.nothing()
  
  
  def test_maybe_map_should_not_call_mapper_when_monad_has_nothing():
      Maybe.nothing().map(wrong_mapper)
  
  
  def test_maybe_fold_should_retrun_result_of_mapper_called_with_maybe_value():
      assert Maybe.just(42).fold(increase) == 43
  
  
  def test_maybe_fold_should_not_call_mapper_when_monad_has_nothing():
      Maybe.nothing().fold(wrong_mapper)
  
  
  def test_maybe_get_or_else_method_should_return_maybe_value_when_monad_is_not_empy():
      assert Maybe.just(42).get_or_else(0) == 42
  
  
  def test_maybe_get_or_else_method_should_return_argument_when_monad_is_emtpy():
      assert Maybe.nothing().get_or_else(0) == 0
  
  
  def test_maybe_is_nothing_should_return_proper_boolean():
      assert Maybe.just(42).is_nothing is False
      assert Maybe.nothing().is_nothing is True
  
  
  def test_maybe_if_filter_returns_false_method_should_return_empty_maybe():
      assert Maybe.just(41).filter(lambda value: value % 2 == 0) == Maybe.nothing()
  
  
  def test_maybe_if_filter_returns_true_method_should_return_self():
      assert Maybe.just(42).filter(lambda value: value % 2 == 0) == Maybe.just(42)
  
subject: fix flake8