presto-rcfile/src/main/java/io/prestosql/rcfile/RcFileReader.java/RcFileReader/getSync
class RcFileReader:    public Slice getSync()
    {
        Slice sync = Slices.allocate(SIZE_OF_LONG + SIZE_OF_LONG);
        sync.setLong(0, syncFirst);
        sync.setLong(SIZE_OF_LONG, syncSecond);
        return sync;
    }