How to iterate all classes in a name space ?

Hi, thank you for your time.

Another name space

MonoGame

MonoGame

is using the name space

GameName

GameName

as showed on the picture.
My idea is that

MonoGame

MonoGame

take each class in

GameName

GameName

and runs the code in it.
is it possible ?

also bonus question : how a program can ignore the fact that something doesn't exist ?