@Override
    public int codePointAt(final char[] chars, final int offset, final int limit) {
     return Character.codePointAt(chars, offset, limit);
    }
Return the index within <code>buf[start:start+count]</code> which is by <code>offset</code>
 code points from <code>index</code>.
linguistics/src/main/java/com/yahoo/language/simple/kstem/CharacterUtils.java