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 process_update_types(self) -> list:
        """
        You need to override this method and return any update types which you want to be processed
        """
        raise NotImplementedError