info: iOS5, xcode4.3.2, iphone5

Create tab view controller application from xcode template wizard.  

Following code gets generated (some truncated by me for this post).

=== SUFirstViewController.h

```
#import <UIKit/UIKit.h>    
@interface SUFirstViewController : UIViewController    
@end

```

=== SUFirstViewController.m

```
    #import "SUFirstViewController.h"    

    @interface SUFirstViewController ()    
    @end

    @implementation SUFirstViewController    
    - (void)viewDidLoad {
        [super viewDidLoad];
        // Do any additional setup after loading the view, typically from a nib.
    }    
    @end

```

===  

My question is regarding this code snippet: 

```
@interface SUFirstViewController ()    
@end

```

Why is this particular code snippet generated in the SUFirstViewController.m ?  

Can I remove it ?  

How do I use it ?