'Given a dictionary of new values, update `item` and return it.
..note: NO validation or deserialization occurs here.'

def update(self, item, new_values, flush=True, **kwargs):

    self.session().add(item)
    for (key, value) in new_values.items():
        if hasattr(item, key):
            setattr(item, key, value)
    if flush:
        self.session().flush()
    return item
