old_contents: #!/usr/bin/env python
  # -*- coding: utf-8 -*-
  
  # pyvows testing engine
  # https://github.com/heynemann/pyvows
  
  # Licensed under the MIT license:
  # http://www.opensource.org/licenses/mit-license
  # Copyright (c) 2011 Bernardo Heynemann heynemann@gmail.com
  
  from pyvows import Vows, expect
  
  
  class SomeClass(object): pass
  class OtherClass(object): pass
  
  @Vows.batch
  class AssertionIsInstance(Vows.Context):
      def topic(self):
          return SomeClass()
  
      class WhenIsInstance(Vows.Context):
  
          def we_get_an_instance_of_someclass(self, topic):
              expect(topic).to_be_instance_of(SomeClass)
  
          class WhenWeGetAnError(Vows.Context):
  
              def topic(self, last):
                  expect(2).to_be_instance_of(str)
  
              def we_get_an_understandable_message(self, topic):
                  expect(topic).to_have_an_error_message_of(
                          'Expected topic(2) to be an instance of {0!s}, but it was a {1!s}.'.format(str, int))
  
      class WhenIsNotInstance(Vows.Context):
  
          def we_do_not_get_an_instance_of_otherclass(self, topic):
              expect(topic).Not.to_be_instance_of(OtherClass)
  
          class WhenWeGetAnError(Vows.Context):
  
              def topic(self, last):
                  expect(2).not_to_be_instance_of(int)
  
              def we_get_an_understandable_message(self, topic):
                  expect(topic).to_have_an_error_message_of(
                          'Expected topic(2) not to be an instance of {0!s}.'.format(int))
  
  
  
new_contents: #!/usr/bin/env python
  # -*- coding: utf-8 -*-
  
  # pyvows testing engine
  # https://github.com/heynemann/pyvows
  
  # Licensed under the MIT license:
  # http://www.opensource.org/licenses/mit-license
  # Copyright (c) 2011 Bernardo Heynemann heynemann@gmail.com
  
  from pyvows import Vows, expect
  
  
  class SomeClass(object):
      pass
  
  
  class OtherClass(object):
      pass
  
  
  @Vows.batch
  class AssertionIsInstance(Vows.Context):
      def topic(self):
          return SomeClass()
  
      class WhenIsInstance(Vows.Context):
  
          def we_get_an_instance_of_someclass(self, topic):
              expect(topic).to_be_instance_of(SomeClass)
  
          class WhenWeGetAnError(Vows.Context):
  
              def topic(self, last):
                  expect(2).to_be_instance_of(str)
  
              def we_get_an_understandable_message(self, topic):
                  expect(topic).to_have_an_error_message_of(
                      'Expected topic(2) to be an instance of {0!s}, but it was a {1!s}.'.format(str, int))
  
      class WhenIsNotInstance(Vows.Context):
  
          def we_do_not_get_an_instance_of_otherclass(self, topic):
              expect(topic).Not.to_be_instance_of(OtherClass)
  
          class WhenWeGetAnError(Vows.Context):
  
              def topic(self, last):
                  expect(2).not_to_be_instance_of(int)
  
              def we_get_an_understandable_message(self, topic):
                  expect(topic).to_have_an_error_message_of(
                      'Expected topic(2) not to be an instance of {0!s}.'.format(int))
  
subject: Add blank lines and fix indenting for flake8