Usage of TypedHandlerDelegate

Greetings!

I'm quite new to plugin development and I trying to implement a custom keystroke handler.

So, I've tried to inherit from TypedHandler, but in this case default editor typing behaviour doesn't appear. 
I found one thread on this forum with pretty same issue, advising to use TypedHandlerDelegate implementation. But I didn't understood, how to combine this classes? So, e.g. I have implementation of TypedHandler, and I can use something like typedAction.setupHandler(myHandler), but how to use TypedHandlerDelegate in this case? 

Google'd a lot, but still hasn't found any information about it.

Thanks!