MaterialState constructor Null safety

1. Flutter
2. material
3. MaterialState
4. MaterialState const constructor

MaterialState enum

1. Constructors
2. MaterialState
3. Values
4. hovered
5. focused
6. pressed
7. dragged
8. selected
9. scrolledUnder
10. disabled
11. error
12. Properties
13. hashCode
14. index
15. runtimeType
16. Methods
17. noSuchMethod
18. toString
19. Operators
20. operator ==
21. Constants
22. values