GroupComparer

public class GroupComparer : IEqualityComparer<group> 
{ 
    public bool Equals(group x, group y) 
    { 
                     return x.distinguishedname.ToString()==y.distinguishedname.ToString(); 
    } 
    public int GetHashCode(group gr) 
    { 
        throw new NotImplementedException(); 
    } 
}