public static boolean isInterComparable(Iterable<?> objects) {
        Iterator<?> iter = objects.iterator();
        if (!iter.hasNext()) {
            return true;
        }
        Object o = iter.next();
        if (o == null || !(o instanceof Comparable)) {
            return false;
        }
        while (iter.hasNext()) {
            Object oo = iter.next();
            if (oo == null || o.getClass() != oo.getClass()) {
                return false;
            }
        }
        return true;
    }