Review

class Utilities {
    /**
     * Check if the value of a character belongs to a certain interval
     * that indicates it's the higher part of a surrogate pair.
     * @param c	the character
     * @return	true if the character belongs to the interval
     * @since	2.1.2
     */
    public static boolean isSurrogateHigh(final char c) {
        return c >= '\ud800' && c <= '\udbff';
    }

}