presto-raptor-legacy/src/main/java/io/prestosql/plugin/raptor/legacy/RaptorMetadata.java/RaptorMetadata/setTransactionId
class RaptorMetadata:    private void setTransactionId(long transactionId)
    {
        checkState(currentTransactionId.compareAndSet(null, transactionId), "current transaction ID already set");
    }