@class CADisplayLink; @interface PKDisplayLinkObserver : NSObject { CADisplayLink *_displayLink; id /* block */ _handler; } - (void)dealloc; - (BOOL)stop; - (id)initWithHandler:(id /* block */)a0; - (void).cxx_destruct; - (void)_displayLinkHandler:(id)a0; - (BOOL)startWithPreferredFramesPerSecond:(struct CAFrameRateRange { float x0; float x1; float x2; })a0 addToRunLoop:(id)a1 forMode:(id)a2; @end