public static IQueryable<TSource> CheckOrderBy<TSource, TKey>(
	this IQueryable<TSource> source,
	Expression<Func<TSource, TKey>> keySelector,
	IComparer<TKey> comparer,
	bool isDescending
)

<ExtensionAttribute> 
Public Shared Function CheckOrderBy(Of TSource, TKey) ( 
	source As IQueryable(Of TSource),
	keySelector As Expression(Of Func(Of TSource, TKey)),
	comparer As IComparer(Of TKey),
	isDescending As Boolean
) As IQueryable(Of TSource)

public:
[ExtensionAttribute]
generic<typename TSource, typename TKey>
static IQueryable<TSource>^ CheckOrderBy(
	IQueryable<TSource>^ source, 
	Expression<Func<TSource, TKey>^>^ keySelector, 
	IComparer<TKey>^ comparer, 
	bool isDescending
)