Objective c expectFutureValue失败

为什么我不能通过考试？未调用任何AFHTTPRequestOperation块。expectFutureValue似乎不等待结果并立即返回。我正在尝试XCode 6.1和Kiwi 2.3.1

谢谢

context(@"AFNetworking", ^{
    it(@"stubs a request with an error", ^{
        NSError *error = [NSError errorWithDomain:@"com.luisobo.nocilla" code:123 userInfo:@{NSLocalizedDescriptionKey:@"Failing, failing... 1, 2, 3..."}];
        stubRequest(@"POST", @"https://example.com/say-hello").
        withHeaders(@{ @"X-MY-AWESOME-HEADER": @"sisisi", @"Content-Type": @"text/plain" }).
        withBody(@"Adios!").
        andFailWithError(error);
        NSURL *url = [NSURL URLWithString:@"https://example.com/say-hello"];
        NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
        [request setHTTPMethod:@"POST"];
        [request setValue:@"text/plain" forHTTPHeaderField:@"Content-Type"];
        [request setValue:@"sisisi" forHTTPHeaderField:@"X-MY-AWESOME-HEADER"];
        [request setHTTPBody:[@"Adios!" dataUsingEncoding:NSASCIIStringEncoding]];
        AFHTTPRequestOperation *operation = [[AFHTTPRequestOperation alloc] initWithRequest:request];
        __block BOOL succeed = NO;
        __block BOOL failed = NO;
        __block NSError *capturedError = nil;
        [operation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) {
            succeed = YES;
        } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
            capturedError = error;
            failed = YES;
        }];
        [operation start];

        [[expectFutureValue(theValue(failed)) shouldEventually] beYes];
    });
});