@Test public void caseSensitive() {

    String unescaped = "Ü ü & &";
    assertEquals("&Uuml; &uuml; &amp; &amp;", Entities.escape(unescaped, Charset.forName("ascii").newEncoder(), Entities.EscapeMode.extended));
    
    String escaped = "&Uuml; &uuml; &amp; &AMP";
    assertEquals("Ü ü & &", Entities.unescape(escaped));
}