def f1(): with yielding(2) as y: for c in chars: y.spawn(f(c)) yield from y
def gen_func(): with yielding(3) as y: for c in 'abcdefghijklmn': y.spawn(g(c)) yield from y
def gen_func(): with yielding() as y: for c in chars: y.spawn(f(c)) yield from y
def gen_func(): with yielding() as y: y.spawn(asyncio.sleep(0.01)) yield from y