public void An_ArgumentException_is_raised()
    {
      // arrange
      var repo = new FooRepository();
      var service = new FooService(repo);

      // act
      service.Execute(Guid.Empty);
    }
    public void A_new_instance_is_created()
    {
      // arrange
      var repository = new FooRepository();

      // act
      var service = new FooService(repository);

      // assert
      Assert.IsInstanceOf<FooService>(service);
    }