UserEvent constructor Null safety

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

UserEvent class

1. Constructors
2. UserEvent
3. Properties
4. hashCode
5. runtimeType
6. Methods
7. noSuchMethod
8. toString
9. Operators
10. operator ==
11. Static methods
12. clear
13. click
14. dblClick
15. deselectOptions
16. hover
17. keyboard
18. keyboardWithDelay
19. paste
20. selectOptions
21. tab
22. type
23. typeWithDelay
24. unhover
25. upload