def _check_backup_source_state(self):
        state = self.backup_source.state
        if state not in self.backup_source.States.STABLE_STATES:
            logger.warning('Cannot execute backup schedule for %s in state %s.' % (self.backup_source, state))
            return False

        return True
Create new nodes and add them to the given cluster.
dataset/ETHPy150Open opennode/nodeconductor/nodeconductor/backup/models.py/BackupSchedule._check_backup_source_state--crossover with--dataset/ETHPy150Open ClusterHQ/flocker/admin/acceptance.py/IClusterRunner.extend_cluster