presto-jdbc/src/main/java/io/prestosql/jdbc/PrestoConnection.java/PrestoConnection/getStartTransactionSql
class PrestoConnection:    String getStartTransactionSql()
            throws SQLException
    {
        return format(
                "START TRANSACTION ISOLATION LEVEL %s, READ %s",
                getIsolationLevel(isolationLevel.get()),
                readOnly.get() ? "ONLY" : "WRITE");
    }