WrapParentData constructor Null safety

1. Flutter
2. rendering
3. WrapParentData
4. WrapParentData constructor

WrapParentData class

1. Constructors
2. WrapParentData
3. Properties
4. hashCode
5. nextSibling
6. offset
7. previousSibling
8. runtimeType
9. Methods
10. detach
11. noSuchMethod
12. toString
13. Operators
14. operator ==