def _start_timer(self):
        if self.active:
            self._setup_timer()
virtual method to get supported oses.
dataset/ETHPy150Open pika/pika/pika/heartbeat.py/HeartbeatChecker._start_timer--crossover with--dataset/ETHPy150Open openstack/compass-core/compass/deployment/installers/installer.py/OSInstaller.get_oses