code: public Appcast fetch(final URL url, Proxy proxy, int connectTimeout, int readTimeout) throws AppcastException {
          return fetch(url, proxy, connectTimeout, readTimeout, null);
      }
docs: Fetch an appcast from the given URL
  
  @param url The update URL
  @param proxy proxy data
  @param connectTimeout the connect timeout in milliseconds
  @param readTimeout the read timeout in milliseconds
  @return The fetched appcast content
  @throws AppcastException in case of an error