code: def backend_routing(self, context):
          
          satosa_logging(logger, logging.DEBUG, "Routing to backend: %s " % context.target_backend, context.state)
          backend = self.backends[context.target_backend]["instance"]
          context.state[STATE_KEY] = context.target_frontend
          return backend
docs: Returns the targeted backend and an updated state
  
          :type context: satosa.context.Context
          :rtype satosa.backends.base.BackendModule
  
          :param context: The request context
          :return: backend