Textkit2 NSTextView textContentStorage is nil

I can't get NSTextView to work in textkit2 with the following code, textView.textContentStorage , textContentStorage.textStorage is both nil. does anyone have a working example? hope there is a Frameworks Engineer help me out, appreciate so much.

import AppKit

open class MyEditor: NSView {
  let textView: NSTextView
  let textLayoutManager: NSTextLayoutManager
  let textContentStorage: NSTextContentStorage

  public init() {
    textLayoutManager = NSTextLayoutManager()
    textContentStorage = NSTextContentStorage()
     
    let textContainer = NSTextContainer(size: NSSize(width: 200, height: 0.0))
    textContainer.widthTracksTextView = true
    textContainer.heightTracksTextView = true
     
    textLayoutManager.textContainer = textContainer
    textContentStorage.addTextLayoutManager(textLayoutManager)
     
    textView = NSTextView(frame: .zero, textContainer: textContainer)
         
    super.init(frame: .zero)
     
    addSubview(textView)
  }
   
  public func setAttributedString(_ attrString: NSAttributedString) {
    print(textView.textContentStorage) // always nil
    textContentStorage.textStorage?.setAttributedString(attrString)
  }
   
  public required init?(coder: NSCoder) {
    return nil
  }
}