[Unsuported]
It allows to make supetest requests inside generators like
let result = yield supertest(app).get(url).end();
for supertest 1.0. It is not required for supertest 2.0+.
With supertest 2.0+ you can use next code without additional libraries.
request.get('/search').expect(200).then(success, failure);
//with co 1.0
yield supertest(app).get('url').expect(200);
//with async/await (co 2.0+, TypeScript, ES7, etc)
await supertest(app).get('url').expect(200);
npm install co-supertest supertest