sclass MultiBencher {
  settable Runnable action;
  settable double seconds = 10;
  settable double interval = 0.001;
  double elapsedSeconds;
  
  new L<BenchForNSeconds> benchers;
  
  *() {}
  *(Runnable *action) {}
  
  run {
    ensureCapacity(benchers, iceilRatio(seconds, interval)+2);
    long start = nanoTime(), endTime = lround(start+secondsToNanos(seconds));
    while (nanoTime() < endTime) {
      var bencher = addAndReturn(benchers, new BenchForNSeconds(interval, action));
      bencher.run();
    }
  }
  
  long startTime() { ret empty(benchers) ? 0 : first(benchers).startTime; }
  
  toString {
    ret lines(mapWithIndex(benchers, (i, b)
      -> "Run " + (i+1) + "/" + l(benchers)
        + " (T+" + n2(lround(nanosToMilliseconds(b.startTime-startTime()))) + " ms): "
        + b));
  }
}