// Load our mapping info.
    NSString* plistPath = [[NSBundle mainBundle] pathForResource:@"modelMapping" ofType:@"plist"];
    NSDictionary* dict  = [NSDictionary dictionaryWithContentsOfFile:plistPath];
    [objectManager loadMappingsFromDictionary:dict];

    // GET Objects
    RKTUserStatus* userStatus = [[RKTUserStatus alloc] init];
    [userStatus setUsername:@"RestKit"];
    [objectManager getObject:userStatus
                        path:nil
                  parameters:nil
                     success:successBlock
                     failure:errorBlock];

    // POST a tweet
    RKTweet* tweet = [_tweets lastObject];
    RKObjectManager *objectManager = [RKObjectManager sharedManager];
    [objectManager postObject:tweet
                         path:nil
                   parameters:nil
                      success:^(RKObjectRequestOperation *operation, RKMappingResult *mappingResult) {
                      } failure:^(RKObjectRequestOperation *operation, NSError *error) {
                          // This will fail, it is only here
                          // to demonstrate that we can easily post an object
                          // and the reverse mapping is resolved by the extension.
                      }];