```func application(_ app: UIApplication, open url: URL, options: [UIApplication.OpenURLOptionsKey : Any] = [:]) -> Bool {
        // Sends the URL to the current authorization flow (if any) which will
        // process it if it relates to an authorization response.
        if let authorizationFlow = self.currentAuthorizationFlow, authorizationFlow.resumeExternalUserAgentFlow(with: url) {
            self.currentAuthorizationFlow = nil
            return true
        }

    return false
}
```