C# inheritance - same identifier on either side of ':'

Question

I know : indicates inheritance in C#;

but what does it mean when the same identifier is on either side?

Eg

class GameObject : GameObject {

Answer 1

It does not work, because Visual Studio will throw a 'cyclic dependency' error, because, when you think about it, GameObject inherits from GameObject which inherits from GameObject which inherits from... In other words, this is impossible, and so means nothing (except, like Neil mentioned in the comments, a compiler error).