<ServiceBehaviorAttribute(InstanceContextMode := InstanceContextMode.PerCall)> _
<AspNetCompatibilityRequirementsAttribute(RequirementsMode := AspNetCompatibilityRequirementsMode.Allowed)> _
Public Class DataService(Of T) _
    Implements IRequestHandler

Dim instance As DataService(Of T)

[ServiceBehaviorAttribute(InstanceContextMode = InstanceContextMode.PerCall)]
[AspNetCompatibilityRequirementsAttribute(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)]
public class DataService<T> : IRequestHandler

[ServiceBehaviorAttribute(InstanceContextMode = InstanceContextMode::PerCall)]
[AspNetCompatibilityRequirementsAttribute(RequirementsMode = AspNetCompatibilityRequirementsMode::Allowed)]
generic<typename T>
public ref class DataService : IRequestHandler

JScript does not support generic types or methods.

namespace AventureworksService
{

    public class AdventureworksSales :
           DataService<AdventureworksEntities>
    { } 

}