1. Constructors
  2. BackButtonDispatcher
  3. Properties
  4. hasCallbacks
  5. hashCode
  6. runtimeType
  7. Methods
  8. addCallback
  9. createChildBackButtonDispatcher
  10. deferTo
  11. forget
  12. invokeCallback
  13. noSuchMethod
  14. removeCallback
  15. takePriority
  16. toString
  17. Operators
  18. operator ==