RouteAware constructor Null safety

1. Flutter
2. widgets
3. RouteAware
4. RouteAware constructor

RouteAware class

1. Constructors
2. RouteAware
3. Properties
4. hashCode
5. runtimeType
6. Methods
7. didPop
8. didPopNext
9. didPush
10. didPushNext
11. noSuchMethod
12. toString
13. Operators
14. operator ==