@Test
public void shouldConvertStringToDatabaseColumn() {

    JsonSetConverter converter = new JsonSetConverter();
    Set<String> set = Sets.newHashSet();
    set.add("element_1");
    set.add("element_2");
    String json = converter.convertToDatabaseColumn(set);
    boolean valid = (json.equalsIgnoreCase("[\"element_1\",\"element_2\"]")
            || json.equalsIgnoreCase("[\"element_2\",\"element_1\"]"));
    assertTrue(valid);
}