@Override
	public String toString() {
		long nanos = elapsedNanos();

		TimeUnit unit = chooseUnit(nanos);
		double value = (double) nanos / NANOSECONDS.convert(1, unit);

		// Too bad this functionality is not exposed as a regular method call
		return String.format(Locale.ROOT, "%.4g", value) + " " + abbreviate(unit);
	}
Returns a string representation of the current elapsed time.
shared/src/main/java/com/oasisfeng/perf/Stopwatch.java