@Test
public void testMapObjectValues() {

    final JsonObject input = obj()
            .key("one", key("num", 1))
            .key("two", key("num", 2))
            .key("three", key("num", 3))
            .get();
    final List<Integer> expected = Arrays.asList(2, 3, 4);
    assertEquals("", expected,
            mapObjectValues(input, (key, value) -> value.getInt("num") + 1,
                    false));
}