text: module.exports = (stage) => {
    // extend router.defaultParam
    stage.filter('request', async (ctx, next) => {
      await next();
  
      const { defaultParam } = ctx.router || {};
  
      if (defaultParam) {
        ctx.param = Object.assign({}, defaultParam, ctx.param);
        Object.assign(ctx.query, ctx.param);
        Object.assign(ctx.reqBody, ctx.param);
      }
    });
  }
  