code: public Connection getConnection() throws SQLException {
          Connection activeConn = null;
  
          if (this.getDataSource() != null) {
  
              // checking if we can reuse last connection
              if (this.conn == null) {
                  this.conn = this.getDataSource().getConnection();
              }
  
              if (this.conn != null) {
                  initConnection(this.conn);
              }
  
          }
  
          if (this.conn == null) {
              throw new SQLException("Null connection");
          }
  
          if (this.conn.getAutoCommit() != false) {
              this.conn.setAutoCommit(false);
          }
  
          if (this.isolationLevel != null) {
              if (this.conn.getTransactionIsolation() != this.isolationLevel.intValue()) {
                  this.conn.setTransactionIsolation(this.isolationLevel);
              }
          }
  
          activeConn = this.conn;
  
          return ConnectionProxy.newInstance(activeConn);
      }
docs: {@inheritDoc}