code: public XAConnection getXAConnection(String user, String password) throws SQLException {
      Connection con = super.getConnection(user, password);
      return new PGXAConnection((BaseConnection) con);
    }
docs: Gets a XA-enabled connection to the PostgreSQL database. The database is identified by the
  DataSource properties serverName, databaseName, and portNumber. The user to connect as is
  identified by the arguments user and password, which override the DataSource properties by the
  same name.
  
  @return A valid database connection.
  @throws SQLException Occurs when the database connection cannot be established.