old_contents: from __future__ import absolute_import
  
  from sentry.utils.services import Service
  
  
  class Newsletter(Service):
      __all__ = (
          'is_enabled', 'get_subscriptions', 'update_subscription', 'create_or_update_subscription'
      )
  
      DEFAULT_LIST_ID = 1
  
      enabled = False
  
      def is_enabled(self):
          return self.enabled
  
      def get_subscriptions(self, user):
          return None
  
      def update_subscription(self, user, **kwargs):
          return None
  
      def create_or_update_subscription(self, user, **kwargs):
          kwargs['create'] = True
          return self.update_subscription(user, **kwargs)
  
new_contents: from __future__ import absolute_import
  
  from sentry.utils.services import Service
  
  
  class Newsletter(Service):
      __all__ = (
          'is_enabled', 'get_subscriptions', 'update_subscription',
          'create_or_update_subscription', 'optout_email',
      )
  
      DEFAULT_LIST_ID = 1
  
      enabled = False
  
      def is_enabled(self):
          return self.enabled
  
      def get_subscriptions(self, user):
          return None
  
      def update_subscription(self, user, **kwargs):
          return None
  
      def create_or_update_subscription(self, user, **kwargs):
          kwargs['create'] = True
          return self.update_subscription(user, **kwargs)
  
      def optout_email(self, email, property):
          raise NotImplementedError
  
subject: Add optout_email method to base newsletter (#6808)