<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 async def reopen(self):
 """ Reopens a match that was marked completed, automatically resetting matches that follow it |methcoro| Raises: APIException """

        res = await self.connection('POST', 'tournaments/{}/matches/{}/reopen'.format(self._tournament_id, self._id))
        self._refresh_from_json(res)