code: private void selectEngine(PacScriptSource pacSource) {
      try {
        log.log(Level.INFO, "Using javax.script JavaScript engine.");
        this.pacScriptParser = new JavaxPacScriptParser(pacSource);
      } catch (Exception e) {
        log.log(Level.INFO, "PAC parser error.", e);
      }
    }
docs: ***********************************************************************
  Selects one of the available PAC parser engines.
  
  @param pacSource
  to use as input.
  **********************************************************************