public void WhenEntityDoesNotExists_ThenThrowEntityNotFound()
 {
     var entityById = Mock.Of<IEntityById>(eb => eb.Exist<Subscription>(It.IsAny<Identity>()) == false);
     var command = new DeleteSubscriptionCommand(entityById, Mock.Of<IRepository<Subscription>>());
     var identity = Identity.Random();
     command.Executing(c => c.Execute(identity))
             .Throws<EntityNotFoundException>();
 }
        public void WhenAllIsOk_ThenDelete()
        {
            var identity = Identity.Random();
            var entityById = Mock.Of<IEntityById>(eb => eb.Exist<Subscription>(It.IsAny<Identity>()) == true);
            var repository = new StubRepository<Subscription>(new Subscription{Id = identity});
            var command = new DeleteSubscriptionCommand(entityById, repository);

            command.Execute(identity);

            repository.Entities.Should().Be.Empty();
        }