iphone - iPhone に Google+ を実装する際にエラーが発生する

Question

iOS チュートリアル用の Google+ を使用して Objective-C iPhone に Google+ を実装していますが、Google+ のサインイン ボタンをクリックすると 、このエラーが発生します。

2013-01-14 14:28:46.168 googleplus_tutorials[2468:11303] GTMMethodCheckMethodChecker: Class WebMIMETypeRegistry does not conform to @protocol(NSObject), so won't be checked
2013-01-14 14:28:46.176 googleplus_tutorials[2468:11303] GTMMethodCheckMethodChecker: Class UIKeyboardCandidateUtilities does not conform to @protocol(NSObject), so won't be checked
2013-01-14 14:28:55.544 googleplus_tutorials[2468:11303] *** Assertion failure in -[GPPSignInButton createGPPSignIn], /Volumes/BuildData/pulse-data/agents/wpyk8.hot/recipes/211255319/base/googlemac/Shared/GooglePlus/Dev/GooglePlusPlatform/GPPSignInButton.m:155
2013-01-14 14:28:55.545 googleplus_tutorials[2468:11303] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'You must specify a client ID for GPPSignInButton.'
*** First throw call stack:
(0x141e012 0x1243e7e 0x141de78 0xcd9f35 0x448c4 0x44688 0x1257705 0x18e920 0x18e8b8 0x24f671 0x24fbcf 0x24ed38 0x1be33f 0x1be552 0x19c3aa 0x18dcf8 0x2301df9 0x2301ad0 0x1393bf5 0x1393962 0x13c4bb6 0x13c3f44 0x13c3e1b 0x23007e3 0x2300668 0x18b65c 0x2e22 0x2d55)
libc++abi.dylib: terminate called throwing an exception

このリンクを使用して、iPhone https://developers.google.com/+/mobile/ios/getting-startedに google+ を実装してい ます。 これが私のコードです

- (void)viewDidLoad
{
    [super viewDidLoad];
  static NSString * const kClientId = @"711430132123.apps.googleusercontent.com";
   GPPShare *share = [[GPPShare alloc] initWithClientID:kClientId];
  signInButton = [[GPPSignInButton alloc]init];
   signInButton.delegate = self;
   signInButton.clientID = kClientId;
signInButton.scope = [NSArray arrayWithObjects:@"https://www.googleapis.com/auth/plus.moments.write",@"https://www.googleapis.com/auth/plus.me",nil];

    AppDelegate *appDelegate = (AppDelegate *)
    [[UIApplication sharedApplication] delegate];

    appDelegate.signInButton = signInButton;
    // Do any additional setup after loading the view, typically from a nib.
}
- (BOOL)application: (UIApplication *)application
            openURL: (NSURL *)url
  sourceApplication: (NSString *)sourceApplication
         annotation: (id)annotation {
    // Handle Google+ sign-in button URL.
    if ([signInButton handleURL:url
               sourceApplication:sourceApplication
                      annotation:annotation]) {
        return YES;
    }
    return NO;
}

このエラーが発生する理由を教えてください。