java.util.List<String> dest = new java.util.ArrayList<>();
        SuggestItem.concatValues(dest);

        assertEquals(0, dest.size());
    }

    @Test
    public void test_concatValues_duplicatesRemoved() {
        java.util.List<String> dest = new java.util.ArrayList<>();
        dest.add("existing");

        SuggestItem.concatValues(dest, "new", "existing", "new", "another");