protected internal virtual IController GetControllerInstance(RequestContext requestContext, Type controllerType)
{
    if (controllerType == null)
    {
        throw new HttpException(0x194, string.Format(CultureInfo.CurrentCulture, MvcResources.DefaultControllerFactory_NoControllerFound, new object[] { requestContext.HttpContext.Request.Path }));
    }
    if (!typeof(IController).IsAssignableFrom(controllerType))
    {
        throw new ArgumentException(string.Format(CultureInfo.CurrentCulture, MvcResources.DefaultControllerFactory_TypeDoesNotSubclassControllerBase, new object[] { controllerType }), "controllerType");
    }
    return this.ControllerActivator.Create(requestContext, controllerType);
}