code: @Override
  	public void rollback() {
  		if (conn != null) {
  			try {
  				conn.rollback();
  			} catch (SQLException e) {
  				throw new UroborosqlSQLException(e);
  			}
  		}
  	}
docs: {@inheritDoc}
  
  @see jp.co.future.uroborosql.connection.ConnectionManager#rollback()