@class BSTimer, NSHashTable; @interface STKIncomingCallUIStateMonitor : NSObject { struct os_unfair_lock_s { unsigned int _os_unfair_lock_opaque; } _observersLock; NSHashTable *_observersLock_observers; BSTimer *_fallbackTimer; struct os_unfair_lock_s { unsigned int _os_unfair_lock_opaque; } _lock; BOOL _lock_showingIncomingCallUI; int _inCallAlertVisibleNotifyToken; } @property (nonatomic) BOOL isShowingIncomingCallUI; + (id)sharedInstance; - (id)init; - (void)removeObserver:(id)a0; - (void)_refreshState; - (void).cxx_destruct; - (void)_setIncomingCallUIState:(BOOL)a0 forReason:(id)a1; - (void)addObserver:(id)a0; - (double)_fallbackTimerDuration; @end