in src/main/java/com/googlesource/gerrit/plugins/reviewnotes/ExportReviewNotes.java [63:78]
  protected void run() throws Failure, InterruptedException {
    if (threads <= 0) {
      threads = 1;
    }
    changes = mergedChanges();
    monitor = new ThreadSafeProgressMonitor(new TextProgressMonitor(stdout));
    monitor.beginTask("Scanning merged changes", changes.size());
    monitor.startWorkers(threads);
    for (int tid = 0; tid < threads; tid++) {
      new Worker().start();
    }
    monitor.waitForCompletion();
    monitor.endTask();
  }