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 gaussian(data, mean, covariance):
    """!
    @brief Calculates gaussian for dataset using specified mean (mathematical expectation) and variance or covariance in case
            multi-dimensional data.