docs: private NodeAVL next(Session session, PersistentStore store, NodeAVL x) {
  
          if (x == null) {
              return null;
          }
  
          readLock.lock();
  
          try {
              while (true) {
                  x = next(store, x);
  
                  if (x == null) {
                      return x;
                  }
  
                  if (session == null) {
                      return x;
                  }
  
                  Row row = x.getRow(store);
  
                  if (session.database.txManager.canRead(session, row)) {
                      return x;
                  }
              }
          } finally {
              readLock.unlock();
          }
      }