I've created IsSubsetOf List extension based on discussion at http://stackoverflow.com/questions/332973/linq-check-whether-an-array-is-a-subset-of-another
///
/// Determines whether a System.Collections.Generic.List object is a subset of the specified collection.
/// http://stackoverflow.com/questions/332973/linq-check-whether-an-array-is-a-subset-of-another
///
///
///
///
public static bool IsSubsetOf(this List coll1, List coll2)
{
bool isSubset = !coll1.Except(coll2).Any();
return isSubset;
}