docs: def update(self, request, *args, **kwargs):
          """
          See the *Annotator* documentation regarding the
          `update <http://docs.annotatorjs.org/en/v1.2.x/storage.html#update>`_
          endpoint.
  
          :param request:
              incoming :class:`rest_framework.request.Request`.
          :return:
              303 :class:`rest_framework.response.Response`.
          """
          response = super(AnnotationViewSet, self).update(request,
                                                           *args,
                                                           **kwargs)
          for h, v in self.get_success_headers(response.data).items():
              response[h] = v
          response.data = None
          response.status_code = status.HTTP_303_SEE_OTHER
          return response