Firebase Integration : user identity login/logout

Good morning,

We’re looking at the Firebase Integration documentation here : https://docs.revenuecat.com/docs/firebase-integration 

In the section about setting the Firebase User Identity in RevenueCat. 

Here:

    // Add state change listener for Firebase Authentication
    Auth.auth().addStateDidChangeListener { (auth, user) in


        if let uid = user?.uid {

            // identify Purchases SDK with new Firebase user
            Purchases.shared.logIn(uid, { (info, created, error) in
                if let e = error {
                    print("Sign in error: \(e.localizedDescription)")
                } else {
                    print("User \(uid) signed in")
                }
            })
        }
    }

It is clear that you call logIn when the user id is available. 

However, why don’t yo call logOut when it is not? 

Is there a reason? We just want to get our implementation right / complete and from an remote point of view, it feels incomplete. 

Thank you