cancelled constant Null safety

1. wings_data_model
2. wings_data_model
3. CarePlanActivityDetailStatus
4. cancelled constant

CarePlanActivityDetailStatus class

1. Properties
2. hashCode
3. name
4. runtimeType
5. Methods
6. noSuchMethod
7. toString
8. Operators
9. operator ==
10. Static properties
11. serializer
12. values
13. Static methods
14. valueOf
15. Constants
16. cancelled
17. completed
18. enteredInError
19. inProgress
20. notStarted
21. onHold
22. scheduled
23. stopped
24. unknown