### Question:
FixedDuration { public FixedDuration(Duration fixedDuration) { this.fixedDuration = fixedDuration; } FixedDuration(Duration fixedDuration); Distance getDistance(Distance sourceDistance, Duration sourceDuration);  }### Answer:
@Test public void testFixedDuration() { DefaultDistance di = DefaultDistance.of(90, DistanceUnit.METERS); DefaultDuration du = DefaultDuration.of(30, TimeUnit.MINUTES); FixedDuration fixedDistance = new FixedDuration(DefaultDuration.of(1, TimeUnit.HOURS)); assertEquals(DefaultDistance.of(180, DistanceUnit.METERS), fixedDistance.getDistance(di, du)); assertEquals(DefaultDistance.of(590.57064, DistanceUnit.FEET), fixedDistance.getDistance(di.convertTo(DistanceUnit.FEET), du)); }