code: @SuppressWarnings("unused")
    public static long nanoTime() {
      if (ShadowLooper.looperMode() == LooperMode.Mode.PAUSED) {
        return TimeUnit.MILLISECONDS.toNanos(SystemClock.uptimeMillis());
      } else {
        return ShadowLegacySystemClock.nanoTime();
      }
    }
docs: Implements {@link System#nanoTime} through ShadowWrangler.
  
  @return Current time with nanos.