@Override
    public V compute(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
        if (key == null) {
            return null;
        }
        return super.compute(key, remappingFunction);
    }
@Test
    public void testCompute() {
        Assert.assertEquals(VALUE, map.get(KEY));
        Assert.assertEquals(null, map.compute(null, (key, value) -> ""));
        Assert.assertEquals(VALUE, map.get(KEY));
    }