System.out.println("removePlanet");
PlanetId pid = PlanetId.Sun;
DefaultPlanetModel instance = pm;
expectEv = PlanetModelEvent.EvType.REMOVE_PLANET;
expectPid = pid;
Planet p01 = instance.removePlanet(pid);
assertEquals(pid, p01.getPlanetId());
assertNull("Missing event", expectEv);
// should not get an event
expectEv = PlanetModelEvent.EvType.REMOVE_PLANET;
expectPid = pid;
Planet p02 = instance.removePlanet(pid);
assertNull("Unexpected planet", p02);
assertNotNull("Unexpected event", expectEv);
}