network_lib_part1.m

- (void)downloadData {
    NSURL *url = [NSURL URLWithString:@"someurlhere"];
    NetworkFetcher *networkFetcher = [[NetworkFetcher alloc] initWithURL:url];
    [networkFetcher startWithCompletionHandler:^(NSData *data){
        NSLog(@"Request URL %@ finished", networkFetcher.url);
        _fetchedData = data;
    }];
}