如何在swift中清除缓存中的uimage？

import UIKit

class ImageCache {
    static let shared = ImageCache()
    private let cache = NSCache<NSString, UIImage>()
    
    private init() {
        // 初始化缓存设置，如缓存大小限制等
    }
    
    func setImage(_ image: UIImage, forKey key: String) {
        cache.setObject(image, forKey: key as NSString)
    }
    
    func image(forKey key: String) -> UIImage? {
        return cache.object(forKey: key as NSString)
    }
    
    func removeImage(forKey key: String) {
        cache.removeObject(forKey: key as NSString)
    }
    
    func clearCache() {
        cache.removeAllObjects()
    }
}

// 清除指定缓存项
ImageCache.shared.removeImage(forKey: "exampleKey")

// 清除所有缓存项
ImageCache.shared.clearCache()