if (slice != null) {
//get Column from main table
String colName = slice.getColumns().get(0).getName();
CnsSubscriptionProtocol protocol = getEndpointAndProtoIndexValProtocol(colName);
String endpoint = getEndpointAndProtoIndexValEndpoint(colName);
CmbComposite columnName = cassandraHandler.getCmbComposite(endpoint, protocol.name());
CmbColumn<CmbComposite, String> column = cassandraHandler.readColumn(AbstractDurablePersistence.CNS_KEYSPACE, columnFamilySubscriptions, Util.getCnsTopicArn(arn), columnName, CMB_SERIALIZER.STRING_SERIALIZER, CMB_SERIALIZER.COMPOSITE_SERIALIZER, CMB_SERIALIZER.STRING_SERIALIZER);
if (column != null) {
CNSSubscription s = extractSubscriptionFromColumn(column, Util.getCnsTopicArn(arn));
s.checkIsValid();