protected boolean isMacAddress(String field, FieldPresence presence) {
        return isMacAddress(object, field, presence);
    }
@Test
    public void isMacAddress() {
        assertTrue("is not proper mac", cfg.isMacAddress(MAC, MANDATORY));
        assertTrue("is not proper mac", cfg.isMacAddress(MAC, OPTIONAL));
        assertTrue("is not proper mac", cfg.isMacAddress("none", OPTIONAL));
        assertTrue("did not detect missing field",
                expectInvalidField(() -> cfg.isMacAddress("none", MANDATORY)));
        assertTrue("did not detect bad ip",
                expectInvalidField(() -> cfg.isMacAddress(BAD_MAC, MANDATORY)));
    }