// store reverse node-id to rel-id for future updates of relationship-records
final ReverseRelationshipMap futureModeRelIdQueueOutgoing;
final ReverseRelationshipMap futureModeRelIdQueueIncoming;
public RelationshipIdHandler(int relsPerNode) {
futureModeRelIdQueueOutgoing = new ConcurrentLongReverseRelationshipMap(relsPerNode);
futureModeRelIdQueueIncoming = new ConcurrentLongReverseRelationshipMap(relsPerNode);
}