      'DeleteModelMixin',
      'ListModelMixin'
  )
  
  #TODO: In RequestMixin and ResponseMixin : get_response_class/get_request_class are a bit ugly. Do we even want to be able to set the parameters on the view ?
  
  ########## Request Mixin ##########
  
  class RequestMixin(object):
      """
 
</s> remove     @property
    def _default_renderer(self):
        """
        Return the view's default renderer class.
        """
        return self.get_renderers()[0]

    @property
    def headers(self):
        """
        Dictionary of headers to set on the response.
        This is useful when the response doesn't exist yet, but you
        want to memorize some headers to set on it when it will exist.
        """
        if not hasattr(self, '_headers'):
            self._headers = {}
        return self._headers

 </s> add  </s> remove         request_class = self.get_request_class()
        return request_class(self.request)
 </s> add         parsers = self.get_parsers()
        request = self.request_class(request, parsers=parsers)
        self.request = request
        return request

    @property
    def _parsed_media_types(self):
        """
        Return a list of all the media types that this view can parse.
        """
        return [p.media_type for p in self.parser_classes] </s> remove def request_class_factory(request):
    """
    Builds and returns a request class, to be used as a replacement of Django's built-in.
    
    In fact :class:`request.Request` needs to be mixed-in with a subclass of `HttpRequest` for use,
    and we cannot do that before knowing which subclass of `HttpRequest` is used. So this function
    takes a request instance as only argument, and returns a properly mixed-in request class.
    """
    request_class = type(request)
    return type(request_class.__name__, (Request, request_class), {})


 </s> add  </s> remove This enhanced request object offers the following :
 </s> add The wrapped request then offer the following :
      'DeleteModelMixin',
      'ListModelMixin'
  )
  

  
  ########## Request Mixin ##########
  
  class RequestMixin(object):
      """
keep keep keep keep replace keep keep keep keep keep
 cleaned Request/Response/mixins to have similar interface 
djangorestframework/mixins.py