old_contents: """TestExtensionManager
  
  Extension manager used only for testing.
  """
  
  import logging
  import warnings
  
  from stevedore import extension
  
  
  LOG = logging.getLogger(__name__)
  
  
  class TestExtensionManager(extension.ExtensionManager):
      """ExtensionManager that is explicitly initialized for tests.
  
      .. deprecated:: 0.13
  
         Use the :func:`make_test_instance` class method of the class
         being replaced by the test instance instead of using this class
         directly.
  
      :param extensions: Pre-configured Extension instances to use
                         instead of loading them from entry points.
      :type extensions: list of :class:`~stevedore.extension.Extension`
      :param namespace: The namespace for the entry points.
      :type namespace: str
      :param invoke_on_load: Boolean controlling whether to invoke the
          object returned by the entry point after the driver is loaded.
      :type invoke_on_load: bool
      :param invoke_args: Positional arguments to pass when invoking
          the object returned by the entry point. Only used if invoke_on_load
          is True.
      :type invoke_args: tuple
      :param invoke_kwds: Named arguments to pass when invoking
          the object returned by the entry point. Only used if invoke_on_load
          is True.
      :type invoke_kwds: dict
  
      """
  
      def __init__(self, extensions,
                   namespace='test',
                   invoke_on_load=False,
                   invoke_args=(),
                   invoke_kwds={}):
          super(TestExtensionManager, self).__init__(namespace,
                                                     invoke_on_load,
                                                     invoke_args,
                                                     invoke_kwds,
                                                     )
          self.extensions = extensions
          warnings.warn(
              'TestExtesionManager has been replaced by make_test_instance()',
              DeprecationWarning)
  
      def _load_plugins(self, invoke_on_load,
                        invoke_args,
                        invoke_kwds):
          return []
  
new_contents: """TestExtensionManager
  
  Extension manager used only for testing.
  """
  
  import logging
  import warnings
  
  from stevedore import extension
  
  
  LOG = logging.getLogger(__name__)
  
  
  class TestExtensionManager(extension.ExtensionManager):
      """ExtensionManager that is explicitly initialized for tests.
  
      .. deprecated:: 0.13
  
         Use the :func:`make_test_instance` class method of the class
         being replaced by the test instance instead of using this class
         directly.
  
      :param extensions: Pre-configured Extension instances to use
                         instead of loading them from entry points.
      :type extensions: list of :class:`~stevedore.extension.Extension`
      :param namespace: The namespace for the entry points.
      :type namespace: str
      :param invoke_on_load: Boolean controlling whether to invoke the
          object returned by the entry point after the driver is loaded.
      :type invoke_on_load: bool
      :param invoke_args: Positional arguments to pass when invoking
          the object returned by the entry point. Only used if invoke_on_load
          is True.
      :type invoke_args: tuple
      :param invoke_kwds: Named arguments to pass when invoking
          the object returned by the entry point. Only used if invoke_on_load
          is True.
      :type invoke_kwds: dict
  
      """
  
      def __init__(self, extensions,
                   namespace='test',
                   invoke_on_load=False,
                   invoke_args=(),
                   invoke_kwds={}):
          super(TestExtensionManager, self).__init__(namespace,
                                                     invoke_on_load,
                                                     invoke_args,
                                                     invoke_kwds,
                                                     )
          self.extensions = extensions
          warnings.warn(
              'TestExtesionManager has been replaced by make_test_instance()',
              DeprecationWarning)
  
      def _load_plugins(self, *args, **kwds):
          return []
  
subject: Fix the test manager implementation