public void Clear_ExistingGuidPassed()
{
var cartID = "9b3df90a-1007-4778-b614-91df990e0c95";
var mockHttpContext = MockHttpSession.setSessionKey(cartID);
_controller.ControllerContext.HttpContext = mockHttpContext.Object;
// Act
_controller.ClearCart();
var okResult = _controller.Get();
var items = Assert.IsType <List <ShoppingCartItemDto> >(okResult.Result);
// Assert
Assert.Empty(items);
}