MGTwitterEngine and Authentication Delegation

Question

Hi. I've been racking my brain for a bit trying figure out what's the cleanest way to handled failed authenication using delegation with the MGTwitterEngine.

Is this the correct usage of the connectionIdentifier or just hacked?

- (void)initiateCredentialCheckWithUsername:(NSString *)username password:(NSString *)password {
    self.authCID = [self.twitterEngine getXAuthAccessTokenForUsername:username password:password];
    self.twitterUsername = username;
}

- (void)requestFailed:(NSString *)requestIdentifier withError:(NSError *)error {
    NSLog(@"%@", error);

    // Failed to login
    if (self.authCID == requestIdentifier) {
         // Alert the user...
    }
}