Type or namespace name Mock HttpContext could not be found

I trying to getting address controller in mvc am getting error type or namespace name Mock HttpContext could not be found

private static AddressesController GetAddressController()
    {
        AddressesController addresscontroller = new AddressesController();
        addresscontroller.ControllerContext = new ControllerContext()
        {
            Controller = addresscontroller,
            RequestContext = new RequestContext(new MockHttpContext(), new RouteData())
        };
        return addresscontroller;
    }