if (topic != null) {
return topic;
} else {
topic = new CNSTopic(arn, name, displayName, userId);
topic.checkIsValid();
cassandraHandler.insertRow(AbstractDurablePersistence.CNS_KEYSPACE, topic.getArn(), columnFamilyTopics, getColumnValues(topic), CMB_SERIALIZER.STRING_SERIALIZER, CMB_SERIALIZER.STRING_SERIALIZER, CMB_SERIALIZER.STRING_SERIALIZER, null);
cassandraHandler.update(AbstractDurablePersistence.CNS_KEYSPACE, columnFamilyTopicsByUserId, userId, topic.getArn(), "", CMB_SERIALIZER.STRING_SERIALIZER, CMB_SERIALIZER.STRING_SERIALIZER, CMB_SERIALIZER.STRING_SERIALIZER, null);
cassandraHandler.delete(AbstractDurablePersistence.CNS_KEYSPACE, columnFamilyTopicStats, arn, null, CMB_SERIALIZER.STRING_SERIALIZER, CMB_SERIALIZER.STRING_SERIALIZER);