Ember Simple Auth - Authorizer not being setup when the session is restored

The code below currently works but If I remove the line with _setup then the outgoing requests don't have the Authorization header.

It doesn't feel like I should be using the _setup function as it isn't in the documentation.

What am I doing wrong?

I'm using the latest version of Ember and Ember-Simple-Auth with the Oauth Password Grant.

Ember.getOwner(this).lookup('authenticator:custom').restore(token).then(() => {
    Ember.getOwner(this).lookup('session:main')._setup('authenticator:custom', token, true);
});