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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def _retry(self, state):
        '''
        Starts a single try of the whole restart path.
        '''
        state.attempt += 1
        self.debug('Starting restart attempt: %d.', state.attempt)
        if self._cmp_strategy(RestartStrategy.buryme):
            self.debug('Agent %r is going to by buried according to his '
                       'last will.', state.factory.descriptor_type)
            return self._send_buried_notifications()
        else:
            f = self._set_restart_flag()
            f.add_callback(fiber.drop_param, self._send_died_notifications)
            f.add_both(self._ensure_someone_took_responsability)
            return f