code: protected boolean accept(String path) {
  
      // GWT Development Mode files
      if (path.equals("hosted.html") || path.endsWith(".devmode.js")) {
        return false;
      }
  
      // Default or welcome file
      if (path.equals("/")) {
        return true;
      }
  
      // Whitelisted file extension
      int pos = path.lastIndexOf('.');
      if (pos != -1) {
        String extension = path.substring(pos + 1);
        if (DEFAULT_EXTENSION_WHITELIST.contains(extension)) {
          return true;
        }
      }
  
      // Not included by default
      return false;
    }
docs: Determines whether our not the given should be included in the app cache
  manifest. Subclasses may override this method in order to filter out
  specific file patterns.
  
  @param path the path of the resource being considered
  @return true if the file should be included in the manifest