code: @Override
  	public URL getURL() throws IOException {
  		URL url = resolveURL();
  		if (url == null) {
  			throw new FileNotFoundException(getDescription() + " cannot be resolved to URL because it does not exist");
  		}
  		return url;
  	}
docs: This implementation returns a URL for the underlying class path resource,
  if available.
  @see java.lang.ClassLoader#getResource(String)
  @see java.lang.Class#getResource(String)