TimeUtils { public static String toMilliseconds(long nano) { return format(nano / NANOSECOND) + "ms"; } private  TimeUtils(); static String toSeconds(long ms); static String toMilliseconds(long nano); static String format(double time); static double getUptime(long uptime); static long getJVMUptime(); static final double MILLISECOND; static final double NANOSECOND; }
@Test void toMilliseconds() { Assertions.assertEquals("1.00ms", TimeUtils.toMilliseconds(1_000_000)); }