code: def cache_data(self, request, data, key='params'):
          
          request.session['%s:%s' % (constants.SESSION_KEY, key)] = data
docs: Cache data in the session store.
  
          :param request: :attr:`django.http.HttpRequest`
          :param data: Arbitrary data to store.
          :param key: `str` The key under which to store the data.