DiagnosticLevel constructor Null safety

1. Flutter
2. foundation
3. DiagnosticLevel
4. DiagnosticLevel const constructor

DiagnosticLevel enum

1. Constructors
2. DiagnosticLevel
3. Values
4. hidden
5. fine
6. debug
7. info
8. warning
9. hint
10. summary
11. error
12. off
13. Properties
14. hashCode
15. index
16. runtimeType
17. Methods
18. noSuchMethod
19. toString
20. Operators
21. operator ==
22. Constants
23. values