@class NSArray, NSString, NSMapTable, NSObject; @protocol OS_os_log, OS_dispatch_queue; @interface HKObserverSet : NSObject { NSString *_name; NSObject<OS_os_log> *_category; struct os_unfair_lock_s { unsigned int _os_unfair_lock_opaque; } _lock; NSMapTable *_queuesByObserver; NSObject<OS_dispatch_queue> *_defaultObserverQueue; } @property (readonly) unsigned long long count; @property (readonly, copy) NSArray *allObservers; - (void)registerObserver:(id)a0 queue:(id)a1; - (void)registerObserver:(id)a0; - (void)notifyObserversInGroup:(id)a0 handler:(id /* block */)a1; - (void)unregisterObserver:(id)a0; - (void)notifyObservers:(id /* block */)a0; - (void).cxx_destruct; - (void)registerObserver:(id)a0 queue:(id)a1 runIfFirstObserver:(id /* block */)a2; - (id)initWithName:(id)a0 loggingCategory:(id)a1; - (void)unregisterObserver:(id)a0 runIfLastObserver:(id /* block */)a1; - (void)notifyObserver:(id)a0 handler:(id /* block */)a1; - (void)unregisterAllObservers; @end