docs: public static String format(long elapsedNs) {
      if (elapsedNs >= ONE_HOUR) {
        long hours = elapsedNs / ONE_HOUR;
        long minutes = (elapsedNs % ONE_HOUR) / ONE_MINUTE;
        return hours + " h " + minutes + " mn";
      } else if (elapsedNs >= ONE_MINUTE) {
        long minutes = elapsedNs / ONE_MINUTE;
        long seconds = (elapsedNs % ONE_MINUTE) / ONE_SECOND;
        return minutes + " mn " + seconds + " s";
      } else if (elapsedNs >= ONE_SECOND) {
        long seconds = elapsedNs / ONE_SECOND;
        long milliseconds = (elapsedNs % ONE_SECOND) / ONE_MILLISECOND;
        return seconds + "." + milliseconds + " s";
      } else if (elapsedNs >= ONE_MILLISECOND) {
        return (elapsedNs / ONE_MILLISECOND) + " ms";
      } else if (elapsedNs >= ONE_MICROSECOND) {
        return (elapsedNs / ONE_MICROSECOND) + " us";
      } else {
        return elapsedNs + " ns";
      }
    }