如何在asnetworkimagenode url请求中添加身份验证头？

import AsyncDisplayKit

// 创建 ASNetworkImageNode 实例
let imageNode = ASNetworkImageNode()

// 设置身份验证凭据
let username = "your_username"
let password = "your_password"
let credentials = "\(username):\(password)"
let encodedCredentials = Data(credentials.utf8).base64EncodedString()

// 创建请求头
let headers = ["Authorization": "Basic \(encodedCredentials)"]

// 设置请求头
imageNode.urlRequestModifier = { [weak self] request in
    var modifiedRequest = request
    modifiedRequest.allHTTPHeaderFields = headers
    return modifiedRequest
}

// 设置图片 URL
let imageURL = URL(string: "https://example.com/image.jpg")
imageNode.url = imageURL