@class NSTimer, NSMapTable; @interface HFSynchronizedTimer : NSObject @property (retain, nonatomic) NSTimer *activeTimer; @property (readonly, nonatomic) NSMapTable *observers; + (id)sharedInstance; - (id)init; - (void)removeObserver:(id)a0; - (void)_timerDidFire; - (void).cxx_destruct; - (void)addObserver:(id)a0; - (void)_updateTimerState; @end