code: async function clearNodeFolder() {
      if (!TMP_FOLDER_BASE || TMP_FOLDER_BASE === '' || TMP_FOLDER_BASE === '/') {
          throw new Error('BroadcastChannel.clearNodeFolder(): path is wrong');
      }
      ENSURE_BASE_FOLDER_EXISTS_PROMISE = null;
      await removeDir(TMP_FOLDER_BASE);
      ENSURE_BASE_FOLDER_EXISTS_PROMISE = null;
      return true;
  }
docs: removes the tmp-folder
  @return {Promise<true>}