https://stackoverflow.com/questions/34281531/ios-9-best-solution-for-parsing-json


https://stackoverflow.com/questions/20077328/objective-c-parse-json-from-url-request/20077594#20077594


[[session dataTaskWithURL:request completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
    // handle response
    NSError *parseError;
    NSDictionary *json = [NSJSONSerialization JSONObjectWithData:data options:0 error:&parseError];
    // do something with `json`
    dispatch_async(dispatch_get_main_queue()), ^{[collectionView reloadData]});
}] resume];