def next(self):
        if self.counter == 0 and self.used:
            raise StopIteration()
        try:
            return self.waiters.get().wait()
        finally:
            self.counter -= 1
Wait for the next result, suspending the current GreenThread until it is available
dataset/ETHPy150Open veegee/guv/guv/greenpool.py/GreenPile.next