         block(alert)
     }
     
-    private func _callback(status: PermissionStatus) {
+    private func callbacks(status: PermissionStatus) {
         callback(status)
         
         for set in sets {

    
    func requestPhotos() {
        PHPhotoLibrary.requestAuthorization { _ in
            self._callback(self.status)
        }
    }
}

        
        dispatch_async(dispatch_get_main_queue()) { [weak self] in
            guard let this = self else { return }
            this.callbacks(this.status)
        }
    }
}