How do you show web view with XML parsed variable in Swift 3?

I'm pretty stuck in showing XML parsed data to web view.

import UIKit
import Fuzi

class ViewController: UIViewController {

@IBOutlet weak var webView: UIWebView!

override func viewDidLoad() {
    super.viewDidLoad()

    let myURLString = "https://www.naver.com"
    var myHTMLString = ""
    guard let myURL = URL(string: myURLString) else {
        print("Error: \(myURLString) doesn't seem to be a valid URL")
        return
    }

    do {
        myHTMLString = try String(contentsOf: myURL, encoding: .ascii)
    } catch let error {
        print("Error: \(error)")
    }

    do {
        let doc = try! HTMLDocument(string: myHTMLString, encoding: String.Encoding.utf8)

        // XPath queries
        if let firstDiv = doc.firstChild(xpath: "//*[@id='PM_ID_ct']/div[@class='container']") {
            print("44444")
            print(firstDiv)
            let body:String = firstDiv
            webView.loadHTMLString(firstDiv as String, baseURL: nil)
        }

    } catch let error{
        print(error)
    }

}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}


}

The XML parsed well but when I put the xml variable into web view it makes an error. The error is:

Cannot convert value of type 'XMLElement' to specified type 'String'

Edit Here is one more try

When I changed

let body:String = firstDiv

to

let body:String = firstDiv.stringValue

It removes all the tags and attributes and remained only texts

stringValue only return strings. The correct method should be:

let body: String = firstDiv.rawXML