Extracting titles from an array of book dictionaries

PropertiesArrayOfDictionaryValuesFromAPI

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    NSMutableArray *arrayOfBooks = [[NSMutableArray alloc]init];
    
    [MPSAPI getBookLibrary:^(NSArray *books) {
        
        for (NSMutableDictionary *book in books) {
            
            NSString *bookTitle = book[@"title"];
            [arrayOfBooks addObject:bookTitle];
        }
    }];
    
}
    
//associated API request: 

+ (void)getBookLibrary:(void (^)(NSArray *))completion {
    
    NSOperationQueue *backgroundqueue =[NSOperationQueue new];
    
    NSString *getURL = [NSString stringWithFormat:@"%@", kMAIN_API_URL];
    NSLog(@"%@", getURL);
    
    AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
    
    [manager GET:getURL
      parameters:nil
         success:^(AFHTTPRequestOperation *task, id responseObject) {
             
             NSLog(@"%@", responseObject);
             [backgroundqueue addOperationWithBlock:^{
                 
                 completion(responseObject);
             }];
             
         }failure:^(AFHTTPRequestOperation *task, NSError *error) {
             
             NSLog(@"Failed: %@", error.localizedDescription);
         }];
}