@Test
public void testHasExtra() throws Exception {

    final Metadata entity = newMetadata(_inc);
    final String extra = "extra data";
    entity.getDataInfo().setExtra(extra);
    Metadata md1 = _repository.save(entity);
    assertFindsCorrectMd(md1, (Specification<Metadata>)hasExtra(extra), true);
    assertEquals(0, _repository.count((Specification<Metadata>)hasExtra("wrong extra")));
}