presto-raptor-legacy/src/main/java/io/prestosql/plugin/raptor/legacy/RaptorSessionProperties.java/RaptorSessionProperties/getOneSplitPerBucketThreshold
class RaptorSessionProperties:    public static int getOneSplitPerBucketThreshold(ConnectorSession session)
    {
        return session.getProperty(ONE_SPLIT_PER_BUCKET_THRESHOLD, Integer.class);
    }