static S renderElapsedTimePleasantly(long ms) {
  double secs = toSeconds(ms)/repetitions;
  if (secs >= 1) formatDouble(secs, 3) + " s";
  double ms = secs*1000;
  if (ms >= 1) ret formatDouble(ms, 3) + " ms";
  double us = ms*1000;
  if (us >= 1) ret formatDouble(us, 3) + " µs";
  double ns = us*1000;
  ret iround(ns) + " ns";
}