firstName property Null safety

1. baguette
2. DrawerHeaderWidget
3. DrawerHeaderWidget
4. firstName property

DrawerHeaderWidget class

1. Constructors
2. DrawerHeaderWidget
3. Properties
4. email
5. firstName
6. hashCode
7. image
8. key
9. lastName
10. margin
11. onPress
12. padding
13. runtimeType
14. Methods
15. build
16. createElement
17. debugDescribeChildren
18. debugFillProperties
19. noSuchMethod
20. toDiagnosticsNode
21. toString
22. toStringDeep
23. toStringShallow
24. toStringShort
25. Operators
26. operator ==