### Question:
Period { public static Period secs(int secs) { return new Seconds(secs); }  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 testSecs() { Period period = Period.secs(456); assertThat(period.timeUnit(), equalTo(TimeUnit.SECONDS)); assertThat(period.howLong(), equalTo(456)); assertThat(period.toString(), equalTo("secs(456)")); }