docs: public static InputStream cacheStream(@javax.annotation.Nonnull final String url, @javax.annotation.Nonnull final String file) throws IOException, NoSuchAlgorithmException, KeyStoreException, KeyManagementException {
      if (new File(file).exists()) {
        return new FileInputStream(file);
      }
      else {
        return new TeeInputStream(get(url), new FileOutputStream(file));
      }
    }