docs: private int[] countXingDataEntries(final Collection<SpatialEntry> entries, final HyperBoundingBox mbr, int[] numOf) {
      for(SpatialEntry entry : entries) {
        if(entry instanceof LeafEntry) {
          numOf[0]++;
          if(SpatialUtil.intersects(mbr, entry)) {
            numOf[1]++;
          }
        }
        else {
          N node = tree.getNode(((DirectoryEntry) entry).getPageID());
          countXingDataEntries(node.getEntries(), mbr, numOf);
        }
      }
      return numOf;
    }