ActionTransformer::refine() method

[fvo...@gmail.com]

Hello, does anybody have an idea why the topic has signature as 

final def refine ...

but rather no 

final protected def refine ...

as it's done for the rest of siblings.
It makes impossible to mixin both `ActionTransformer` and `ActionFilter` to one class.
(what is probably not intended though)
or is it a "typo bug"?

Thanks!