code: public static void clearSavedProgress(Context context, Object url) {
          if (url == null) {
              SharedPreferences spn = context.getSharedPreferences("JZVD_PROGRESS",
                      Context.MODE_PRIVATE);
              spn.edit().clear().apply();
          } else {
              SharedPreferences spn = context.getSharedPreferences("JZVD_PROGRESS",
                      Context.MODE_PRIVATE);
              spn.edit().putLong("newVersion:" + url.toString(), 0).apply();
          }
      }
docs: if url == null, clear all progress
  
  @param context context
  @param url     if url!=null clear this url progress