device_flow_grant.swift

let google: Provider = .google(clientID: "", clientSecret: "")
google.scopes = ["email", "profile"]

google.authorize(getCode: { code, url in
    // prompt user to visit url and enter code
}) { result in
    switch result {  
    case .success(let token):
        print(token)
    case .failure(let error):
        print(error)
    }
}

I'm afraid that 'getCode' is not enough to communicate to the client that he is kicking off a device authentication flow and not just "a" code.