objective-c - afnetworking从接口中得到数据，怎么把数据放在另外的变量里呢

(NSArray *)model{
if (_model == nil) {

[UIApplication sharedApplication].networkActivityIndicatorVisible = YES;

NSString *domainStr = @"http://122.200.77.206:8899/ishop/ePlatform/mobile/queryAllMerchants.do";

AFHTTPSessionManager *manager = [AFHTTPSessionManager manager];
manager.requestSerializer = [AFHTTPRequestSerializer serializer];
manager.responseSerializer = [AFHTTPResponseSerializer serializer];

[manager GET:domainStr parameters:nil success:^(NSURLSessionDataTask * _Nonnull task, id  _Nonnull responseObject) {
    // 隐藏系统风火轮
    [UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
    
    //json解析
    NSDictionary *resultDic = [NSJSONSerialization JSONObjectWithData:responseObject options:NSJSONReadingMutableLeaves error:nil];

// NSLog(@"%@",resultDic);

    
    SVJSONModel *jsonModel = [[SVJSONModel alloc]initWithDictionary:resultDic error:nil];
    
    return jsonModel.data;
} failure:^(NSURLSessionDataTask * _Nonnull task, NSError * _Nonnull error) {
    // 解析失败隐藏系统风火轮(可以打印error.userInfo查看错误信息)
    [UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
    NSLog(@"%@",error.userInfo);
    
}];

}

}