TreeWalker class

1. Constructors
2. TreeWalker
3. Properties
4. currentNode
5. filter
6. root
7. whatToShow
8. hashCode
9. runtimeType
10. Methods
11. firstChild
12. lastChild
13. nextNode
14. nextSibling
15. parentNode
16. previousNode
17. previousSibling
18. noSuchMethod
19. toString
20. Operators
21. operator ==