CharUtils.append(buf, 0x10000);
assertEquals(2, buf.length());
assertEquals(CharUtils.getHighSurrogate(0x10000), buf.charAt(0));
assertEquals(CharUtils.getLowSurrogate(0x10000), buf.charAt(1));
assertTrue(CharUtils.isSurrogatePair(buf.charAt(0), buf.charAt(1)));
Codepoint codepoint = CharUtils.codepointAt(buf, 0);
assertEquals(0x10000, codepoint.getValue());
assertEquals(2, codepoint.getCharCount());
assertTrue(codepoint.isSupplementary());
CharUtils.insert(buf, 0, codepoint.next());
assertEquals(4, buf.length());
assertEquals(CharUtils.codepointAt(buf, 0), codepoint.next());
}