Bug Official documentation is outdated

Hi, I found that the official documentation for writing custom control is outdated and doesn't work.

https://docs.unity3d.com/Manual/UIE-UXML.html

Especially,

Code (CSharp):

1. class StatusBar : VisualElement
2. {
3.     public class Factory : UxmlFactory<StatusBar, Traits> {}
4.  
5.     public class Traits : VisualElement.UxmlTraits
6.     {
7.         UxmlStringAttributeDescription m_Status = new UxmlStringAttributeDescription { name = "status" };
8.        
9.         public override IEnumerable<UxmlChildElementDescription> uxmlChildElementsDescription
10.         {
11.             get { yield break; }
12.         }
13.  
14.         public override void Init(VisualElement ve, IUxmlAttributes bag, CreationContext cc)
15.         {
16.             base.Init(ve, bag, cc);
17.             ((StatusBar)ve).status = m_Status.GetValueFromBag(bag, cc);
18.         }
19.     }
20.  
21.     // ...
22. }

should be fixed to:

Code (CSharp):

1. class StatusBar : VisualElement
2. {
3.     public new class UxmlFactory : UxmlFactory<StatusBar, Traits> {}
4.  
5.     public new class UxmlTraits : VisualElement.UxmlTraits
6.     {
7.         UxmlStringAttributeDescription m_Status = new UxmlStringAttributeDescription { name = "status" };
8.        
9.         public override IEnumerable<UxmlChildElementDescription> uxmlChildElementsDescription
10.         {
11.             get { yield break; }
12.         }
13.  
14.         public override void Init(VisualElement ve, IUxmlAttributes bag, CreationContext cc)
15.         {
16.             base.Init(ve, bag, cc);
17.             ((StatusBar)ve).status = m_Status.GetValueFromBag(bag, cc);
18.         }
19.     }
20.  
21.     // ...
22. }