code: void errorDownload(OfflineDownloadOptions offlineDownload, String error, String errorMessage) {
      stateChangeDispatcher.onError(offlineDownload, error, errorMessage);
      offlineDownloads.remove(offlineDownload);
    }
docs: Called when the OfflineDownloadService produced an error while downloading
  
  @param offlineDownload the offline download that produced an error
  @param error           short description of the error
  @param errorMessage    full description of the error
  @since 0.1.0