
// tests if layer can be optional
layer Foo.Bar.Cons2;
SoUrCe RooT Mixin.Cons2 
abstract class MyClass$$Mixin$Cons2 extends AstNode { 
   int one;
}
SoUrCe  Mixin.path 
 class MyClass extends  MyClass$$Mixin$Cons2  { 
   int foobar;
}