generic helper awaitable to synchronize awaiters chronologically on a first-come first-served basis

bouncer.py

class bouncer(Awaitable):
    "serve awaiters on a first-come first-served basis"

    queue = []

    def __init__(self):
        type(self).queue.append(self.caller)

    @property
    def caller(self):
        return current_task().get_coro()

    def __await__(self):
        while True:
           if self.caller == type(self).queue[0]:
               type(self).queue.pop(0)
               return
           else:
              yield