code: def set_public_limits(self):
          
          if self.request.method.upper() in ['GET', 'HEAD']:
              self._query_params.process_int_param('_limit', 20)
          if self._auth_enabled and not getattr(self.request, 'user', None):
              wrappers.set_public_limits(self)
docs: Set public limits if auth is enabled and user is not
          authenticated.
  
          Also sets default limit for GET, HEAD requests.