boolean isAll() {
        return (from == null || (from == AbstractIndex.NULL && isFromInclusive()))
                &&  (to == null);
    }
@Test
    void isAll() {
        assertFalse(pointer(singleton(5)).isAll());
        assertFalse(IS_NULL.isAll());
        assertFalse(IS_NOT_NULL.isAll());
        assertTrue(ALL.isAll());
        assertTrue(ALL_ALT.isAll());
    }