function* sleep(ms, val) {
  return yield new Promise(r => setTimeout(() => r(val), ms))
}
function* test(fl, time = 1e3) {
  yield 0
  return fl ? yield* sleep(time, 'reg') : yield 2
}
function* each() {
  let sum = 0
  for(let i = 0; i < 1e6; i++)
    sum += yield* test()
  return yield sum
}
function* test2() {
  Promise.resolve().then(() => console.log('after'))  
  console.log('sum:', yield* each())
  
  Promise.resolve().then(() => console.log('before sleep'))
  for(let i = 10; i--; )
    console.log(`r${i}=`, yield* test(1, 100))
  
  console.log('sum:', yield* each())
}
asyncWrapper(test2)