assertEquals(NONE, NONE.intersectWith(both));
assertEquals(NONE, both.intersectWith(NONE));
assertEquals(NONE, fun.intersectWith(NONE));
assertEquals(NONE, NONE.intersectWith(fun));
assertEquals(NONE, both.intersectWith(fun2));
assertEquals(both, ALL.intersectWith(both));
assertEquals(both, both.intersectWith(ALL));
assertEquals(fun, ALL.intersectWith(fun));
assertEquals(fun, fun.intersectWith(ALL));