private static long nanos(final InstantSource clock) {
		final Instant now = clock.instant();
		return now.getEpochSecond()*NanoClock.NANOS_PER_SECOND + now.getNano();
	}
Return a new timer object which uses the given clock for measuring the
execution time.

@param clock the clock used for measuring the execution time
@return a new timer
jenetics/src/main/java/io/jenetics/engine/Timing.java