class AVLGroupTree extends AbstractCollection<Centroid> implements Serializable {

    @SuppressWarnings("WeakerAccess")
    public int floor(double centroid) {
        int floor = IntAVLTree.NIL;
        for (int node = tree.root(); node != IntAVLTree.NIL; ) {
            final int cmp = Double.compare(centroid, mean(node));
            if (cmp <= 0) {
                node = tree.left(node);
            } else {
                floor = node;
                node = tree.right(node);
            }
        }
        return floor;
    }

      AVLGroupTree();
      AVLGroupTree(final boolean record);

}