shape property Null safety

1. Flutter
2. material
3. DrawerThemeData
4. shape property

DrawerThemeData class

1. Constructors
2. DrawerThemeData
3. Properties
4. backgroundColor
5. elevation
6. hashCode
7. runtimeType
8. scrimColor
9. shape
10. width
11. Methods
12. copyWith
13. debugFillProperties
14. noSuchMethod
15. toDiagnosticsNode
16. toString
17. toStringShort
18. Operators
19. operator ==
20. Static methods
21. lerp