@interface OriginalObject : NSObject
@end
		
// Define a class which we will swizzle
@implementation OriginalObject
+ (BOOL)isSubclassOfClass:(Class)aClass { return YES; }
+ (NSString *)classMethod { return @"original"; }
+ (NSString *)description { return @"original"; }
- (NSString *)instanceMethod { return @"original"; }
- (NSString *)description { return @"original"; }
@end
		
// All methods on this class which are present on the class that
// it is swizzled to (including superclasses) are called instead of their
// original implementation. The original implementaion can be accessed with the 
// _orig(TYPE, ...) macro and the implementation of the superclass of the class which
// it was swizzled to can be access with the _super(TYPE, ...) macro
// hook(TargetClass) defines a class for
// you that will get swizzled automatically on launch with the TargetClass
hook(OriginalObject)
// Returns YES
+ (BOOL)isSubclassOfClass:(Class)aClass { return _orig(BOOL); }

// Returns "original_replaced"
- (NSString *)className { return [_orig(NSString *) stringByAppendingString:@"_replaced"]; }

// Returns "replaced" when called on the OriginalObject class
+ (NSString *)classMethod { return @"replaced"; }

// Returns the default description implemented by NSObject
+ (NSString *)description { return _super(NSString *); }

// Returns "replaced" when called on an instance of OriginalObject
- (NSString *)instanceMethod { return @"replaced"; }
	
// Returns the default description implemented by NSObject
- (NSString *)description { return _super(NSString *); }
	
// This method is added to instances of OriginalObject and can be called
// like any normal function on OriginalObject
- (void)addedMethod { NSLog(@"this method was added to OriginalObject"); }
endhook

// ZKSwizzle(SOURCE, DST) is a macro shorthand for calling 
// ZKSwizzleInterface handles this step for you, but you will
// have to call it manually if you don't use ZKSwizzleInterface
+swizzleClass:forClass: on ZKSwizzle
ZKSwizzle(ReplacementObject, OriginalObject);

// gets the value of _myIvar on self
int myIvar = ZKHookIvar(self, int, "_myIvar");
	
// gets the pointer to _myIvar on self so you can reassign it
int *myIvar = &ZKHookIvar(self, int, "_myIvar");
// set the value of myIvar on the object
*myIvar = 3;

@interface GroupClass : NSObject
+ (NSString *)classMethod;
- (NSString *)instanceMethod;
@end

@implementation GroupClass
+ (NSString *)classMethod { return @"classMethod"; }
- (NSString *)instanceMethod { return @"instanceMethod"; }
@end

hook(GroupClass, Yosemite)
+ (NSString *)classMethod { return @"swizzled"; }
- (NSString *)instanceMethod { return @"swizzled"; }
endhook

hook(GroupClass, Mavericks)
+ (NSString *)classMethod { return @"swizzled2"; }
- (NSString *)instanceMethod { return @"swizzled2"; }
endhook

ctor {
    int ver = 1;
    ver == 1 ? ZKSwizzleGroup(Yosemite) : ZKSwizzleGroup(Mavericks);
}