@Test
public void testComparingJsonKeys() {

    final Checklist.JsonKeys keys = Checklist.keys();
    final JsonObject obj1 = key("id", keys.checks()).get();
    final JsonObject obj2 = key("id", keys.cndNames()).get();
    final JsonObject obj3 = key("id", keys.cndUrls()).get();
    final JsonObject[] inputValues1 = new JsonObject[]{obj2, obj3, obj1};
    final JsonObject[] expectValues1 = new JsonObject[]{obj1, obj2, obj3};
    Arrays.sort(inputValues1, Checklist.comparingJsonKeys(obj -> obj.getString("id")));
    assertArrayEquals("sort keys using json extractor",
            expectValues1, inputValues1);
}