@class NSObject; @protocol OS_dispatch_queue; @interface MSVCallback : NSObject @property (copy, nonatomic) id block; @property (retain, nonatomic) NSObject<OS_dispatch_queue> *queue; + (id)callbackWithQueue:(id)a0 block:(id)a1; - (void)invoke; - (void)invokeWithObject:(id)a0; - (void).cxx_destruct; @end