docs: @Override
    public void setTransactionIsolation(int level) throws SQLException
    {
      logger.debug(
          "void setTransactionIsolation(int level), level = {}", level);
      raiseSQLExceptionIfConnectionIsClosed();
      if (level == Connection.TRANSACTION_NONE
          || level == Connection.TRANSACTION_READ_COMMITTED)
      {
        this.transactionIsolation = level;
      }
      else
      {
        throw new SQLFeatureNotSupportedException(
            "Transaction Isolation " + level + " not supported.",
            FEATURE_UNSUPPORTED.getSqlState(),
            FEATURE_UNSUPPORTED.getMessageCode());
      }
    }