LogLevel constructor Null safety

1. Flutter
2. webdriver.sync_io
3. LogLevel
4. LogLevel constructor

LogLevel class

1. Constructors
2. LogLevel
3. Properties
4. hashCode
5. runtimeType
6. Methods
7. noSuchMethod
8. toString
9. Operators
10. operator ==
11. Constants
12. all
13. debug
14. info
15. off
16. severe
17. warning