@interface CNUnfairLock : NSObject <NSLocking> { struct os_unfair_lock_s { unsigned int _os_unfair_lock_opaque; } _os_unfair_lock; } - (id)init; - (void)lock; - (void)assertCurrentThreadIsOwner; - (void)unlock; - (id)description; - (BOOL)tryLock; - (void)assertCurrentThreadIsNotOwner; @end