public long elapsed(TimeUnit desiredUnit) {
    return desiredUnit.convert(elapsedNanos(), NANOSECONDS);
  }
Returns the current elapsed time shown on this stopwatch, expressed in the desired time unit,
with any fraction rounded down.

<p>Note that the overhead of measurement can be more than a microsecond, so it is generally not
useful to specify {@link TimeUnit#NANOSECONDS} precision here.
src/main/java/com/google/maps/internal/ratelimiter/Stopwatch.java