presto-main/src/main/java/io/prestosql/operator/exchange/LocalPartitionGenerator.java/LocalPartitionGenerator/processRawHash
class LocalPartitionGenerator:    private static int processRawHash(long rawHash)
    {
        // mix the bits so we don't use the same hash used to distribute between stages
        return (int) XxHash64.hash(Long.reverse(rawHash));
    }