如何删除WKWebView中的缓存？

任何一个合作过的人WKWebView并尝试清除缓存？如果是，该怎么做？有什么例子吗？

P.S. : Normal NSURLCache不管用。

更新的 Swift 5 版本：

WKWebsiteDataStore.default().removeData(ofTypes: [WKWebsiteDataTypeDiskCache, WKWebsiteDataTypeMemoryCache], modifiedSince: Date(timeIntervalSince1970: 0), completionHandler:{ })

斯威夫特版本：

if #available(iOS 9.0, *) {
  let websiteDataTypes = NSSet(array: [WKWebsiteDataTypeDiskCache, WKWebsiteDataTypeMemoryCache])
  let date = NSDate(timeIntervalSince1970: 0)
  WKWebsiteDataStore.defaultDataStore().removeDataOfTypes(websiteDataTypes as! Set<String>, modifiedSince: date, completionHandler:{ })
} else {
    var libraryPath = NSSearchPathForDirectoriesInDomains(NSSearchPathDirectory.LibraryDirectory, NSSearchPathDomainMask.UserDomainMask, false).first!
    libraryPath += "/Cookies"

    do {
      try NSFileManager.defaultManager().removeItemAtPath(libraryPath)
    } catch {
      print("error")
    }
    NSURLCache.sharedURLCache().removeAllCachedResponses()
}

斯威夫特 3 版本：

   if #available(iOS 9.0, *)
    {
        let websiteDataTypes = NSSet(array: [WKWebsiteDataTypeDiskCache, WKWebsiteDataTypeMemoryCache])
        let date = NSDate(timeIntervalSince1970: 0)
        
        WKWebsiteDataStore.default().removeData(ofTypes: websiteDataTypes as! Set<String>, modifiedSince: date as Date, completionHandler:{ })
    }
    else
    {
        var libraryPath = NSSearchPathForDirectoriesInDomains(FileManager.SearchPathDirectory.libraryDirectory, FileManager.SearchPathDomainMask.userDomainMask, false).first!
        libraryPath += "/Cookies"
        
        do {
            try FileManager.default.removeItem(atPath: libraryPath)
        } catch {
            print("error")
        }
        URLCache.shared.removeAllCachedResponses()
    }