public void testToHex() throws Exception {
        assertEquals("010203", StringUtil.toHex(new byte[] { 1, 2, 3 }));
    }

    /**
     * @throws Exception
     */
    @Test
    public void testToHex2() throws Exception {
        assertEquals("0001", StringUtil.toHex(1));
    }

    /**
     * @throws Exception
     */
    @Test
    public void testAppendHex() throws Exception {