docs: private void reinsertExpanded(SpatialPrimitiveDistanceFunction<V> distFunction, DeLiCluTree index, IndexTreePath<DeLiCluEntry> path, DataStore<KNNList> knns) {
      int l = 0; // Count the number of components.
      for(IndexTreePath<DeLiCluEntry> it = path; it != null; it = it.getParentPath()) {
        l++;
      }
      ArrayList<IndexTreePath<DeLiCluEntry>> p = new ArrayList<>(l - 1);
      // All except the last (= root).
      IndexTreePath<DeLiCluEntry> it = path;
      for(; it.getParentPath() != null; it = it.getParentPath()) {
        p.add(it);
      }
      assert (p.size() == l - 1);
      DeLiCluEntry rootEntry = it.getEntry();
      reinsertExpanded(distFunction, index, p, l - 2, rootEntry, knns);
    }