docs: async def update_notifications(self, on_match_open: bool = None, on_tournament_end: bool = None):
          """ update participants notifications for this tournament
  
          |methcoro|
  
          Args:
              on_match_open: Email registered Challonge participants when matches open up for them
              on_tournament_end: Email registered Challonge participants the results when this tournament ends
  
          Raises:
              APIException
  
          """
          params = {}
          if on_match_open is not None:
              params['notify_users_when_matches_open'] = on_match_open
          if on_tournament_end is not None:
              params['notify_users_when_the_tournament_ends'] = on_tournament_end
          assert_or_raise(len(params) > 0, ValueError, 'At least one of the notifications must be given')
          await self.update(**params)