co(function *(){
let promiseA = makeHttpRequestA()
let promiseB = makeHttpRequestBFromA(yield promiseA)
var res = new Foobar(yield promiseA, yield promiseB);
})(); co(function *(){
let promiseA = makeHttpRequestA()
let promiseB = makeHttpRequestBFromA(yield promiseA)
var res = new Foobar(yield promiseA, yield promiseB);
})(); val res = async {
val a = await(makeHttpRequestA())
val b = await(makeHttpRequestBFromA(a))
new Foobar(a, b)
}