A decorator that registers another function as an external
        event listener. Basically this allows you to listen to multiple
        events from different places e.g. such as :func:`.on_ready`

        The functions being listened to must be a coroutine.

        Example
        --------

        .. code-block:: python3

            @bot.listen()
            async def on_message(message):
                print('one')

            # in some other file...

            @bot.listen('on_message')
            async def my_message(message):
                print('two')

        Would print one and two in an unspecified order.

        Raises
        -------
        TypeError
            The function being listened to is not a coroutine.

def listen(self, name=None):
        """A decorator that registers another function as an external
        event listener. Basically this allows you to listen to multiple
        events from different places e.g. such as :func:`.on_ready`

        The functions being listened to must be a coroutine.

        Example
        --------

        .. code-block:: python3

            @bot.listen()
            async def on_message(message):
                print('one')

            # in some other file...

            @bot.listen('on_message')
            async def my_message(message):
                print('two')

        Would print one and two in an unspecified order.

        Raises
        -------
        TypeError
            The function being listened to is not a coroutine.
        """

        def decorator(func):
            self.add_listener(func, name)
            return func

        return decorator