code: public void pauseAll() {
          List<Integer> list = mThreadPool.getAllExactRunningDownloadIds();
  
          if (FileDownloadLog.NEED_LOG) {
              FileDownloadLog.d(this, "pause all tasks %d", list.size());
          }
  
          for (Integer id : list) {
              pause(id);
          }
      }
docs: Pause all running task