Can not get api response `AssertionError [ERR_ASSERTION]: headers have already been sent`
My api is this code
But I can't get a correct response, console will log error `AssertionError [ERR_ASSERTION]: headers have already been sent`
How could I get a right correct response ?

```
  api.post('/v1/users/signup', parseSignup, async (ctx, next) => {
    return sequelize.transaction(async () => {
      ctx.status = HTTPStatus.CREATED;
      ctx.body = {
        key: 'test'
      };
      await next();
    }).catch(error => {
      console.log('api error =', error);
    });
  });
```