For : http://corgitoergosum.net/2014/01/07/ios-coding-conventions-cont/

PSHCoverFeedViewController - properties lazy initializers

- (NSDateFormatter*)dateFormatter
{
    if (!_dateFormatter) {
        _dateFormatter = [[NSDateFormatter alloc] init];
        [_dateFormatter setDateFormat:@"MMMM d"];
    }
    return _dateFormatter;
}

- (NSArray*)feedItemsArray
{
    if (!_feedItemsArray) {
        _feedItemsArray = [@[] mutableCopy];
    }
    return _feedItemsArray;
}

- (PSHFacebookDataService*)facebookDataService
{
    if (!_facebookDataService){
        _facebookDataService = [PSHFacebookDataService sharedService];
    }
    return _facebookDataService;
}

- (UIPageViewController*)feedsPageViewController
{
    if (!_feedsPageViewController){
        _feedsPageViewController = [[UIPageViewController alloc] initWithTransitionStyle:UIPageViewControllerTransitionStyleScroll navigationOrientation:UIPageViewControllerNavigationOrientationHorizontal options:nil];
        _feedsPageViewController.dataSource = self;
        [self addChildViewController:_feedsPageViewController];
        [self.view addSubview:_feedsPageViewController.view];
        [_feedsPageViewController didMoveToParentViewController:self];
    }
    return _feedsPageViewController;
}

-(PSHMenuViewController*) menuViewController
{
    if (!_menuViewController){
        _menuViewController = [[PSHMenuViewController alloc] init];
        _menuViewController.delegate = self;
        
        [self addChildViewController:_menuViewController];
        [_menuViewController didMoveToParentViewController:self];
        self.menuView = _menuViewController.view;
        
        [self.menuViewController animateHideMenuButtons];
    }
    return _menuViewController;
}