def _clone_vdi(session, vdi_to_clone_ref):
    vdi_ref = session.call_xenapi('VDI.clone', vdi_to_clone_ref)
    LOG.debug('Cloned VDI %(vdi_ref)s from VDI '
              '%(vdi_to_clone_ref)s',
              {'vdi_ref': vdi_ref, 'vdi_to_clone_ref': vdi_to_clone_ref})
    return vdi_ref
set is_read=False when user gets mentioned
dataset/ETHPy150Open BU-NU-CLOUD-SP16/Trusted-Platform-Module-nova/nova/virt/xenapi/vm_utils.py/_clone_vdi--crossover with--dataset/ETHPy150Open nitely/Spirit/spirit/topic/notification/tests.py/TopicNotificationModelsTest.test_topic_notification_notify_new_mentions_unactive