def save_last_sync(self, ids, process):
        try:
            spec = {'_id': 'last_sync'}
            document = {'$set': {process: ids}}
            self.db.internal.update(spec, document, upsert=True)
        except Exception as e:
            raise DatabaseException(e)
def __expectation_step(self):
        self.__gaussians = [ [] for _ in range(self.__amount_clusters) ]
        for index in range(self.__amount_clusters):
            self.__gaussians[index] = gaussian(self.__data, self.__means[index], self.__variances[index])