MultiChildLayoutParentData constructor Null safety

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

MultiChildLayoutParentData class

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