#import <UIKit/UIKit.h>

@protocol FooBarDelegate;

@interface FooBar: UIViewController

// Delegate property of the class
@property (nonatomic, weak) id<FooBarDelegate> delegate;

@end

// Delegate

@protocol FooBarDelegate <NSObject>

@required
-(void)requiredDelegateMethod;

@optional
-(void)optionalDelegateMethodOne;
-(void)optionalDelegateMethodTwo:(NSString *)withArgument;

@end