internal static object CreateInstanceFromVirtualPath(
                        VirtualPath virtualPath,
                        Type requiredBaseType,
                        HttpContext context,
                        bool allowCrossApp
                    )
{
    ITypedWebObjectFactory objectFactory = GetVirtualPathObjectFactory(virtualPath, context, allowCrossApp);
    if (objectFactory == null) return null;

    // Make sure it has the required base type (VSWhidbey 516771)
    Util.CheckAssignableType(requiredBaseType, objectFactory.InstantiatedType);

    // impersonate client while executing page ctor (see ASURT 89712)
    // (compilation is done while not impersonating client)

    Object instance;
    using (new ClientImpersonationContext(context))
    {
        instance = objectFactory.CreateInstance();
    }

    return instance;
}