Extension for AppendUserAgent function

gistfile1.txt

private enum Constants {
    static let userAgentJavascript = "navigator.userAgent"
}

extension WKWebView {
    func appendUserAgent(_ valueToAppend: String?) {
        guard let valueToAppend = valueToAppend else { return }
        
        let group = DispatchGroup()
        let queue = DispatchQueue.main
        
        group.enter()
        queue.async(group: group) {
                self.evaluateJavaScript(Constants.userAgentJavascript) { (result, _) in
                    if let result = result as? String {
                        self.customUserAgent = result + valueToAppend
                    }
                    group.leave()
                }
        }
        
        group.wait()
        
    }
}