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 __update_mean(self, rc, mc):
        mean = 0.0
        for index_point in range(len(self.__data)):
            mean += rc[index_point] * self.__data[index_point]