public async Task DeleteUserSendsUserQueryWithCorrectUserId()
        {
            var mediator = new Mock<IMediator>();
            
            const string userId = "foo_id";
            mediator.Setup(x => x.SendAsync(It.Is<UserQuery>(q => q.UserId == userId))).ReturnsAsync(new EditUserModel());
            var controller = new SiteController(null, null, mediator.Object);

            await controller.DeleteUser(userId);
            mediator.Verify(m =>m.SendAsync(It.Is<UserQuery>(q =>q.UserId == userId)), Times.Once);
        }
        public async Task DeleteUserReturnsTheCorrectViewModel()
        {
            var mediator = new Mock<IMediator>();
            const string userId = "foo_id";
            mediator.Setup(x => x.SendAsync(It.IsAny<UserQuery>())).ReturnsAsync(new EditUserModel());
            var controller = new SiteController(null, null, mediator.Object);            

            var result = await controller.DeleteUser(userId);
            var model = ((ViewResult)result).ViewData.Model as DeleteUserModel;

            Assert.Equal(model.UserId, userId);
            Assert.IsType<DeleteUserModel>(model);
        }