public void SolarSystemObjectHelperMoonTest()
        {
            var list = CelestialObjectHelper.GetMainMoons(CelestialObject.Earth).ToList();

            Assert.Single(list);

            list = CelestialObjectHelper.GetAllMoons(CelestialObject.Earth).ToList();
            Assert.Single(list);

            list = CelestialObjectHelper.GetMainMoons(CelestialObject.Jupiter).ToList();
            Assert.Equal(4, list.Count);

            list = CelestialObjectHelper.GetAllMoons(CelestialObject.Jupiter).ToList();
            Assert.Equal(5, list.Count);
        }
        public void SolarSystemObjectHelperMoonThrowsTest()
        {
            Assert.Throws <ArgumentException>(() => CelestialObjectHelper.GetMainMoons(CelestialObject.Moon));

            Assert.Throws <ArgumentException>(() => CelestialObjectHelper.GetAllMoons(CelestialObject.Amalthea));
        }