1@interface Foo(RightSub) <P2>
2@property id right_sub_prop;
3@end
4
5@interface Foo() {
6@public
7  int right_sub_ivar;
8}
9@end
10
11@protocol P4
12- (void)p4_method;
13@property (retain) id p4_prop;
14@end
15
16@interface Foo(LeftP4) <P4>
17@end
18