func sleepCtx(ctx context.Context, duration time.Duration) {
	derivedCtx, _ := context.WithDeadline(ctx, time.Now().Add(duration))
	<-derivedCtx.Done()
}
func sleepCtx(ctx context.Context, duration time.Duration) {
	derivedCtx, _ := context.WithDeadline(ctx, time.Now().Add(duration))
	<-derivedCtx.Done()
}
func sleepCtx ( ctx context . Context , duration time . Duration ) { derivedCtx , _ := context . WithDeadline ( ctx , time . Now ( ) . Add ( duration ) ) <- derivedCtx . Done ( ) }
// sleepCtx provides a cancelable sleep
sleepCtx provides a cancelable sleep