C# has had a similar mindset but different approach; Classes are not 'final'(in C#, 'sealed') by default, nor are methods, BUT they are not considered virtual b

C# has had a similar mindset but different approach; Classes are not 'final'(in C#, 'sealed') by default, nor are methods, BUT they are not considered virtual by default. This still makes inheritance more 'opt-in' than 'opt-out', but still facilitates the use of 'container' classes. It's still open for expansion but you can't -really- change the implementation.