public AclBindingFilter toFilter() {
        return new AclBindingFilter(pattern.toFilter(), entry.toFilter());
    }
@Test
    public void testMatchesAtMostOne() {
        assertNull(ACL1.toFilter().findIndefiniteField());
        assertNull(ACL2.toFilter().findIndefiniteField());
        assertNull(ACL3.toFilter().findIndefiniteField());
        assertFalse(ANY_ANONYMOUS.matchesAtMostOne());
        assertFalse(ANY_DENY.matchesAtMostOne());
        assertFalse(ANY_MYTOPIC.matchesAtMostOne());
    }