text: class NullManager(object):
      """
          This class exists to have the same interface as the
          shelf.hook.manager except do nothing. This will
          be used in the case that a "hookCommand" is not
          configured.
      """
      def notify_artifact_uploaded(self, identity):
          """
              Args:
                  identity(shelf.resource_identity)
          """
          pass
  
      def notify_metadata_updated(self, identity):
          """
              Args:
                  identity(shelf.resource_identity)
          """
          pass
  