def commit(self, base, top, relative=False):
        flags = relative and libvirt.VIR_DOMAIN_BLOCK_COMMIT_RELATIVE or 0
        return self._guest._domain.blockCommit(
            self._disk, base, top, self.COMMIT_DEFAULT_BANDWIDTH, flags=flags)
Create a volume backup of the given volume.
dataset/ETHPy150Open BU-NU-CLOUD-SP16/Trusted-Platform-Module-nova/nova/virt/libvirt/guest.py/BlockDevice.commit--crossover with--dataset/ETHPy150Open openstack/rally/rally/plugins/openstack/scenarios/cinder/utils.py/CinderScenario._create_backup