assertNull(permissionHelper.encode("(allow){user}  "));
        assertNull(permissionHelper.encode("(deny){group}\t\n"));
    }

    @Test
    public void test_encode_decode_symmetry() {
        String[] testValues =
                { "guest", "{user}guest", "{group}guest", "{role}guest", "(deny){user}guest", "(deny){group}guest", "(deny){role}guest" };

        for (String value : testValues) {