docs: private void expandDirNodes(SpatialPrimitiveDistanceFunction<V> distFunction, DeLiCluNode node1, DeLiCluNode node2) {
      if(LOG.isDebuggingFinest()) {
        LOG.debugFinest("ExpandDirNodes: " + node1.getPageID() + " + " + node2.getPageID());
      }
      int numEntries_1 = node1.getNumEntries();
      int numEntries_2 = node2.getNumEntries();
  
      // insert all combinations of unhandled - handled children of
      // node1-node2 into pq
      for(int i = 0; i < numEntries_1; i++) {
        DeLiCluEntry entry1 = node1.getEntry(i);
        if(!entry1.hasUnhandled()) {
          continue;
        }
        for(int j = 0; j < numEntries_2; j++) {
          DeLiCluEntry entry2 = node2.getEntry(j);
  
          if(!entry2.hasHandled()) {
            continue;
          }
          double distance = distFunction.minDist(entry1, entry2);
          heap.add(new SpatialObjectPair(distance, entry1, entry2, true));
        }
      }
    }