async def add_waiter(self):
loop = asyncio.get_event_loop()<EOL>async with self.lock:<EOL><INDENT>waiter = AioEventWaiter(loop)<EOL>self.waiters.add(waiter)<EOL><DEDENT>return waiter<EOL>
Add a :class:`AioEventWaiter` to the :attr:`waiters` container

        The event loop to use for :attr:`AioEventWaiter.loop` is found in the
        current context using :func:`asyncio.get_event_loop`

        Returns:
            waiter: The created :class:`AioEventWaiter` instance