<ExtensionAttribute()>
Public Shared Function ThenBySelector(Of TSource)( _
   ByVal source As IOrderedQueryable(Of TSource), _
   ByVal sortSelector As ISortSelector _
) As IOrderedQueryable(Of TSource)

Dim source As IOrderedQueryable(Of TSource)
Dim sortSelector As ISortSelector
Dim value As IOrderedQueryable(Of TSource)
 
value = QueryableExtensions.ThenBySelector(Of TSource)(source, sortSelector)

[ExtensionAttribute()]
public static IOrderedQueryable<TSource> ThenBySelector<TSource>( 
   IOrderedQueryable<TSource> source,
   ISortSelector sortSelector
)

[ExtensionAttribute()]
public:
static IOrderedQueryable<TSource^>^ ThenBySelectorgeneric<typename TSource>
( 
   IOrderedQueryable<TSource^>^ source,
   ISortSelector^ sortSelector
) 

public void ThenBySample1() {
  var mgr = new DomainModelEntityManager();
  var selector1 = new SortSelector(typeof(Customer), "Country");
  var selector2 = new SortSelector(typeof(Customer), "CompanyName");
  var results = mgr.Customers.OrderBySelector(selector1).ThenBySelector(selector2).ToList();
}