Missing link from SecuredAction to Authenticator

I am using Silhouette for authentication in my Play Scala app. In my flow after successful Sign-in the user is redirected to a SecuredAction API. The user sends the Cookie in this request to the server. What I am not able to understand is the link from SecuredAction code to calling Authenticator for decrypting and deserializing the contents of received Cookie. Looking at the source code of “silhouette/api/actions/SecuredAction.scala” I could not find any connection for calling “deserialize” method in Authenticator.
Note that I am using CookieAuthenticator (after this I am going to switch to JWTAuthenticator).

Authentication will be handled in the RequestHandler which the most actions rely on.