text: //
  //  UIViewController+GKCategory.h
  //  GKAudioPlayerDemo
  //
  //  Created by QuintGao on 2017/9/8.
  //  Copyright © 2017年 高坤. All rights reserved.
  //
  
  #import <UIKit/UIKit.h>
  
  @interface UIViewController (GKWYCategory)
  
  - (UIViewController *)visibleViewControllerIfExist;
  
  @end
  