### Question:
JpaTagRepository implements TagRepository { @Override public Tag save(Tag item) { JpaTag tag = converter.convert(item); return saveOrUpdate(tag.getEntityId(), manager, tag); }  @Override List<Tag> getAll(); @Override List<Tag> getLimitedList(int offset, int limit); @Override Class<? extends Tag> getType(); @Override int getCountAll(); @Override JpaTag getByKeyword(String keyword); @Override Tag get(String id); @Override Tag save(Tag item); @Override void delete(Tag item);  }### Answer:
@Test(expected = NullPointerException.class) @Transactional @Rollback(true) public void save_null(){ Tag tag = null; tag = repository.save(tag); assertNull(tag); }