def insert(self, doc, synced=False):
        doc.id = self.get_next_id()
        doc.synced = synced
        try:
            self.db.docs.insert(doc)
        except Exception as e:
            raise DatabaseException(e)
        return doc
def due_date(self):
        """ Returns a date object of the todo's due date. """
        return self.get_date(config().tag_due())