old_contents: from website.addons.s3.serializer import S3Serializer
  
  class S3Provider(object):
      """An alternative to `ExternalProvider` not tied to OAuth"""
  
      name = 'Amazon S3'
      short_name = 's3'
      provider_name = 's3'
      serializer = S3Serializer
  
      def __init__(self, account=None):
          super(S3Provider, self).__init__()
  
          # provide an unauthenticated session by default
          self.account = account
  
      def __repr__(self):
          return '<{name}: {status}>'.format(
              name=self.__class__.__name__,
              status=self.account.provider_id if self.account else 'anonymous'
          )
  
new_contents: from website.addons.s3.serializer import S3Serializer
  
  class S3Provider(object):
      """An alternative to `ExternalProvider` not tied to OAuth"""
  
      name = 'Amazon S3'
      short_name = 's3'
      serializer = S3Serializer
  
      def __init__(self, account=None):
          super(S3Provider, self).__init__()
  
          # provide an unauthenticated session by default
          self.account = account
  
      def __repr__(self):
          return '<{name}: {status}>'.format(
              name=self.__class__.__name__,
              status=self.account.provider_id if self.account else 'anonymous'
          )
  
subject: Remove unused var