I am creating a new file using Xcode's navigation based application and I see that the .m file has these lines:

```
@interface RootViewController ()
- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath;
@end

```

Why is that declared on .m and not on .h itself?

wouldn't it be easier to just put one line (this one below) on the header file?

```
- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath;

```

I have seen this kind of approach in other codes. I am still learning Objective-C and I wonder why is that.

thanks.