public void ExistsInWorksCorrectly()
        {
            Assert.False(BaseUnits.Undefined.IsSubsetOf(siBaseUnits));
            Assert.False(siBaseUnits.IsSubsetOf(BaseUnits.Undefined));

            var meterBaseUnits = new BaseUnits(LengthUnit.Meter);

            Assert.True(meterBaseUnits.IsSubsetOf(siBaseUnits));

            // Not all units in siBaseUnits will exist in meterBaseUnits
            Assert.False(siBaseUnits.IsSubsetOf(meterBaseUnits));
        }
 public void IsSubsetOfReturnsFalseWithNull()
 {
     Assert.False(siBaseUnits.IsSubsetOf(null));
 }