public ISet <string> GetAccreditedSetExceptResult(ISet <string> first, ISet <string> second)
{
if (first == null)
{
throw new ArgumentNullException(nameof(first));
}
if (second == null)
{
throw new ArgumentNullException(nameof(second));
}
RangeSet <string> set = new RangeSet <string>(this.rangeInfo);
set.UnionWith(first);
set.ExceptWith(second);
return(set);
}