          """
          self.history.insert(0, self.now)
          cache.set(self.key, self.history, self.duration)
          header = 'status=SUCCESS; next=%s sec' % self.next()
          self.view.add_header('X-Throttle', header)
  
      def throttle_failure(self):
          """
          Called when a request to the API has failed due to throttling.
          Raises a '503 service unavailable' response.
 
</s> remove         self.view.add_header('X-Throttle', header)
 </s> add         self.view.headers['X-Throttle'] = header </s> remove             self.initial(request, *args, **kwargs)
 </s> add             # `initial` is the opportunity to temper with the request, 
            # even completely replace it.
            self.request = request = self.initial(request, *args, **kwargs) </s> remove         except ErrorResponse, exc:
            self.assertEqual(exc.response.raw_content, {'field_errors': {'qwerty': ['This field is required.']}})
 </s> add         except ErrorResponse, response:
            self.assertEqual(response.raw_content, {'field_errors': {'qwerty': ['This field is required.']}}) </s> remove         except ErrorResponse, exc:
            self.assertEqual(exc.response.raw_content, {'field_errors': {'qwerty': ['This field is required.']}})
 </s> add         except ErrorResponse, response:
            self.assertEqual(response.raw_content, {'field_errors': {'qwerty': ['This field is required.']}})
        self.view.headers['X-Throttle'] = header
          """
          self.history.insert(0, self.now)
          cache.set(self.key, self.history, self.duration)
          header = 'status=SUCCESS; next=%s sec' % self.next()
        self.view.headers['X-Throttle'] = header
  
      def throttle_failure(self):
          """
          Called when a request to the API has failed due to throttling.
          Raises a '503 service unavailable' response.
keep keep keep keep replace keep keep keep keep keep
 Response as a subclass of HttpResponse - first draft, not quite there yet. 
djangorestframework/permissions.py