public static LongRef ofLong(long value) {
        return new LongRef(value);
    }
@Test
    public void testLongRef() {
        PrimitiveRef.LongRef ref = PrimitiveRef.ofLong(5L);
        assertEquals(5L, ref.value++);
        assertEquals(6L, ref.value);
        assertEquals(7L, ++ref.value);
        assertEquals(7L, ref.value);
    }