code: private File getEffectiveVisitorDirectory ()
    {
      if (this.visitorDirectory != null)
        return this.visitorDirectory;
      if (this.outputDirectory != null)
        return new File (this.outputDirectory, getLastPackageName (getEffectiveVisitorPackageName ()));
      return null;
    }
docs: Gets the absolute path to the output directory for the visitor files.
  
  @return The absolute path to the output directory for the visitor, only
  <code>null</code> if neither {@link #outputDirectory} nor
  {@link #visitorDirectory} have been set.