def start(self, initial_delay=<NUM_LIT:0>):
if self.listener is None:<EOL><INDENT>raise exceptions.NoAsyncListenerError<EOL><DEDENT>elif self._future is not None:<EOL><INDENT>return None<EOL><DEDENT>self._atv.playstatus_revision = <NUM_LIT:0><EOL>self._future = asyncio.ensure_future(<EOL>self._poller(initial_delay), loop=self._loop)<EOL>return self._future<EOL>
Wait for push updates from device.

        Will throw NoAsyncListenerError if no listner has been set.