public void UserLogOff()
        {
            // Arrange
            IBootStrapper bootStrapperMock = Substitute.For<IBootStrapper>();
            IUserRepositoryProxy userRepositoryProxy = Substitute.For<IUserRepositoryProxy>();
            IUserController userController = new UserController(userRepositoryProxy, bootStrapperMock);

            userRepositoryProxy.CheckIfUserExistsInDatabase("Karol").Returns(true);
            userRepositoryProxy.GetTokenForUser("Karol").Returns(new UserManagementService.TOKEN());
            userRepositoryProxy.RemoveTokenFromDatabase(null);

            // Act
            string result = userController.UserLogOff("Karol");

            // Assert
            Assert.AreEqual("User has been logged off", result);
            userRepositoryProxy.ReceivedWithAnyArgs().CheckIfUserExistsInDatabase(null);
            userRepositoryProxy.ReceivedWithAnyArgs().GetTokenForUser("Karol");
            userRepositoryProxy.ReceivedWithAnyArgs().RemoveTokenFromDatabase(null);
        }