AEM 6.3 TokenAuthenticationHandler missing

[CristianD94]

Greetings!

I'm trying to implement a custom SAML authentication implementation. In older code (6.1 I think), there used to be a TokenAuthenticationHandler from which I could call the .getRepositoryId(encapsulatedToken) method. Now, I can't find the TokenAuthenticationHandler class, in the uber-jar-6.3.0 the Impl folder seems to be empty.

Why is it gone and how should I go about finding a replacement?

Thank you!