/**
  * Prepare the ViPR BlockSnapshotSession instance for the pass BlockSnapshot instance.
  *
  * @param snapshot A reference to the snapshot.
  * @return A reference to the newly created snapshot session.
  */
 private BlockSnapshotSession prepareSnapshotSession(BlockSnapshot snapshot) {
   s_logger.info("Prepare BlockSnapshotSession for snapshot {}", snapshot.getId());
   BlockSnapshotSession snapshotSession = new BlockSnapshotSession();
   URI snapSessionURI = URIUtil.createId(BlockSnapshotSession.class);
   snapshotSession.setId(snapSessionURI);
   snapshotSession.setSessionLabel(getSessionLabelFromSettingsInstance(snapshot));
   URI cgURI = snapshot.getConsistencyGroup();
   if (NullColumnValueGetter.isNullURI(cgURI)) {
     snapshotSession.setParent(snapshot.getParent());
     snapshotSession.setLabel(snapshot.getLabel());
   } else {
     snapshotSession.setConsistencyGroup(cgURI);
     snapshotSession.setLabel(snapshot.getSnapsetLabel());
     Volume parent = getDbClient().queryObject(Volume.class, snapshot.getParent());
     if (parent != null) {
       snapshotSession.setReplicationGroupInstance(parent.getReplicationGroupInstance());
       snapshotSession.setSessionSetName(parent.getReplicationGroupInstance());
     }
   }
   snapshotSession.setProject(snapshot.getProject());
   snapshotSession.setStorageController(snapshot.getStorageController());
   snapshotSession.setSessionInstance(snapshot.getSettingsInstance());
   StringSet linkedTargets = new StringSet();
   linkedTargets.add(snapshot.getId().toString());
   snapshotSession.setLinkedTargets(linkedTargets);
   return snapshotSession;
 }