docs: private void expandNodes(DeLiCluTree index, SpatialPrimitiveDistanceFunction<V> distFunction, SpatialObjectPair nodePair, DataStore<KNNList> knns) {
      DeLiCluNode node1 = index.getNode(((SpatialDirectoryEntry) nodePair.entry1).getPageID());
      DeLiCluNode node2 = index.getNode(((SpatialDirectoryEntry) nodePair.entry2).getPageID());
  
      if(node1.isLeaf()) {
        expandLeafNodes(distFunction, node1, node2, knns);
      }
      else {
        expandDirNodes(distFunction, node1, node2);
      }
  
      index.setExpanded(nodePair.entry2, nodePair.entry1);
    }