All callbacks

ViewController.m

#pragma mark - AsyncURLWrapper delegates
- (void) didFinish: (NSData*) data sender: (AsyncURLWrapper*) blob 
{
    if (blob == _asyncWrapper1) {
        NSLog(@"string from wrapper 1: %@", [AsyncURLWrapper asUTF8String:data]);
    }
    if (blob == _asyncWrapper2) {
        NSLog(@"string from wrapper 2: %@", [AsyncURLWrapper asUTF8String:data]);
    }
}

- (void) didFail: (NSError*) error sender: (AsyncURLWrapper*) blob
{
    NSLog(@"%@", error);
}

- (void) didUpdateProgress: (float) percentCompleted sender: (AsyncURLWrapper*) blob
{
   NSLog(@"completed: %@ of %@", percentCompleted, blob);
}

- (void) beforeRetry: (NSError*) error sender: (AsyncURLWrapper*) blob
{
    //Do something before you retry: Login for example
   NSLog(@"before retry for: %@", blob);
}