code: private void copyResources(File outputDirectory) throws IOException
      {
          copyClasspathResource(outputDirectory, "reportng.css", "reportng.css");
          copyClasspathResource(outputDirectory, "reportng.js", "reportng.js");
          // If there is a custom stylesheet, copy that.
          File customStylesheet = META.getStylesheetPath();
  
          if (customStylesheet != null)
          {
              if (customStylesheet.exists())
              {
                  copyFile(outputDirectory, customStylesheet, CUSTOM_STYLE_FILE);
              }
              else
              {
                  // If not found, try to read the file as a resource on the classpath
                  // useful when reportng is called by a jarred up library
                  InputStream stream = ClassLoader.getSystemClassLoader().getResourceAsStream(customStylesheet.getPath());
                  if (stream != null)
                  {
                      copyStream(outputDirectory, stream, CUSTOM_STYLE_FILE);
                  }
              }
          }
      }
docs: Reads the CSS and JavaScript files from the JAR file and writes them to
  the output directory.
  @param outputDirectory Where to put the resources.
  @throws IOException If the resources can't be read or written.