old_contents: # -*- coding: utf-8 -*-
  
  from __future__ import unicode_literals, absolute_import
  
  
  class SearchBackend(object):
      def update(self, *args, **kwargs):
          """
          Method that creates or updates some document
          on the search engine.
          """
          raise NotImplementedError()
  
      def search(self, *args, **kwargs):
          """
          Makes a search and return a result.
          """
          raise NotImplementedError()
  
      def flush(self):
          """
          Send flush/commit command to the
          search engine.
          """
          raise NotImplementedError()
  
  
  class Field(object):
      """
      Base class for any field.
      """
  
      name = None
  
      def __init__(self, **kwargs)
          self.options = kwargs
  
      def set_name(self, name):
          self.name = name
  
new_contents: # -*- coding: utf-8 -*-
  
  from __future__ import unicode_literals, absolute_import
  
  
  class SearchBackend(object):
      pass
  
  
  class Field(object):
      """
      Base class for any field.
      """
  
      name = None
  
      def __init__(self, **kwargs)
          self.options = kwargs
  
      def set_name(self, name):
          self.name = name
  
subject: Remove unnedded fields.