<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def do_callback(self, pkt):
 """Add the callback to the event loop, we use call soon because we just want it to be called at some point, but don't care when particularly. """

        callback, parser = self.get_callback_parser(pkt)

        if asyncio.iscoroutinefunction(callback):
            self.loop.call_soon_threadsafe(self._do_async_callback,
                                           callback, parser)
        else:
            self.loop.call_soon(callback, parser)