presto-rcfile/src/main/java/io/prestosql/rcfile/RcFileWriteValidation.java/WriteChecksumBuilder/build
class WriteChecksumBuilder:        public WriteChecksum build()
        {
            return new WriteChecksum(
                    totalRowCount,
                    rowGroupHash.hash(),
                    columnHashes.stream()
                            .map(XxHash64::hash)
                            .collect(toList()));
        }