code: @Override
    protected ESuccess execute () throws Exception
    {
      final String [] args = generateArguments ();
  
      if (this.outputDirectory != null && !this.outputDirectory.exists ())
      {
        this.outputDirectory.mkdirs ();
      }
  
      LOCK.lock ();
      try
      {
        final com.helger.pgcc.jjtree.JJTree jjtree = new com.helger.pgcc.jjtree.JJTree ();
        return jjtree.main (args);
      }
      finally
      {
        LOCK.unlock ();
      }
    }
docs: {@inheritDoc}