docs: long addBarrierNode(long nodeId) {
          ReaderNode newNode;
          int graphIndex = getNodeMap().get(nodeId);
          if (graphIndex < TOWER_NODE) {
              graphIndex = -graphIndex - 3;
              newNode = new ReaderNode(createNewNodeId(), nodeAccess, graphIndex);
          } else {
              graphIndex = graphIndex - 3;
              newNode = new ReaderNode(createNewNodeId(), pillarInfo, graphIndex);
          }
  
          final long id = newNode.getId();
          prepareHighwayNode(id);
          addNode(newNode);
          return id;
      }