//!!!could the begin and last be removed and just use long.MinValue, etc????
public static RangeCollection Except(this RangeCollection rangeCollectionMain, RangeCollection rangeCollectionToSubtract, long fullRangeBegin, long fullRangeLast)
{
if (rangeCollectionToSubtract.IsEmpty)
{
return(rangeCollectionMain);
}
RangeCollection rangeCollection = rangeCollectionMain.Complement(fullRangeBegin, fullRangeLast);
rangeCollection.AddRangeCollection(rangeCollectionToSubtract);
RangeCollection result = rangeCollection.Complement(fullRangeBegin, fullRangeLast);
return(result);
}