Notification class

1. Constructors
2. Notification
3. Properties
4. actions
5. badge
6. body
7. data
8. dir
9. icon
10. image
11. lang
12. maxActions
13. onClick
14. onClose
15. onError
16. onShow
17. permission
18. renotify
19. requireInteraction
20. silent
21. tag
22. timestamp
23. title
24. vibrate
25. hashCode
26. on
27. runtimeType
28. Methods
29. close
30. addEventListener
31. dispatchEvent
32. noSuchMethod
33. removeEventListener
34. toString
35. Operators
36. operator ==
37. Static properties
38. supported
39. Static methods
40. requestPermission
41. Constants
42. clickEvent
43. closeEvent
44. errorEvent
45. showEvent