def _mark_master_dead(self, master):
        '''
        Mark a master as dead. This will start the sign-in routine
        '''
        # if its connected, mark it dead
        if self._syndics[master].done():
            syndic = self._syndics[master].result()  # pylint: disable=no-member
            self._syndics[master] = syndic.reconnect()
        else:
            # TODO: debug?
            log.info(
                'Attempting to mark %s as dead, although it is already '
                'marked dead', master
            )
Mark a master as dead. This will start the sign-in routine