id property Null safety

1. Flutter
2. vm_service
3. OpenFile
4. id property

OpenFile class

1. Constructors
2. OpenFile
3. Properties
4. hashCode
5. id
6. json
7. lastReadTime
8. lastWriteTime
9. name
10. readBytes
11. readCount
12. runtimeType
13. type
14. writeBytes
15. writeCount
16. Methods
17. noSuchMethod
18. toJson
19. toString
20. Operators
21. operator ==
22. Static methods
23. parse