gistfile1.m

@interface BaseProperty: NSObject
@property NSString *name;
@end

@implementation BaseProperty
@end

@interface ChildProperty: BaseProperty
@property NSString *nickName;
@end

@implementation ChildProperty
@end

@interface MainOwner: NSObject
@property BaseProperty *property;
@end

@implementation MainOwner
@end

@interface ChildOwner: MainOwner
@property ChildProperty *property;
@end

@implementation ChildOwner
@end