code property Null safety

1. Flutter
2. vm_service
3. Frame
4. code property

Frame class

1. Constructors
2. Frame
3. Properties
4. code
5. function
6. hashCode
7. index
8. json
9. kind
10. location
11. runtimeType
12. type
13. vars
14. Methods
15. noSuchMethod
16. toJson
17. toString
18. Operators
19. operator ==
20. Static methods
21. parse