### Question:
InstantRange extends Range<Instant> { public static InstantRange before(final Instant before) { if (before == null) { throw new IllegalArgumentException("range before instant cannot be null"); } return new InstantRange(Instant.MIN, before.minusMillis(1)); } private  InstantRange(final Instant lowerBound, final Instant upperBound); static InstantRange all(); static InstantRange now(); static InstantRange today(); static InstantRange atDate(final LocalDate date); static InstantRange after(final Instant after); static InstantRange before(final Instant before); static InstantRange inTheFuture(); static InstantRange inThePast();  }### Answer:
@Test public void cannotBeBeforeNull() { thrown.expect(IllegalArgumentException.class); thrown.expectMessage("range before instant cannot be null"); InstantRange.before(null); }