SpecialChars constructor Null safety

1. react_testing_library
2. user_event
3. SpecialChars
4. SpecialChars constructor

SpecialChars class

1. Constructors
2. SpecialChars
3. Properties
4. hashCode
5. runtimeType
6. Methods
7. noSuchMethod
8. toString
9. Operators
10. operator ==
11. Constants
12. arrowDown
13. arrowLeft
14. arrowRight
15. arrowUp
16. backspace
17. delete
18. end
19. enter
20. escape
21. home
22. selectAll
23. space
24. whitespace