### Question:
Period { public static Period millis(int millis) { return new Milliseconds(millis); }  abstract int howLong(); abstract TimeUnit timeUnit(); abstract long getEndMillis(long from); static Period millis(int millis); static Period secs(int secs); static Period mins(int mins);  }### Answer:
@Test public void testMillis() { Period period = Period.millis(123); assertThat(period.timeUnit(), equalTo(TimeUnit.MILLISECONDS)); assertThat(period.howLong(), equalTo(123)); assertThat(period.toString(), equalTo("millis(123)")); }