split method Null safety

1. baguette
2. CalendarMarker
3. CalendarMarker
4. split method

CalendarMarker class

1. Constructors
2. CalendarMarker
3. Properties
4. data
5. endDate
6. hashCode
7. label
8. mode
9. runtimeType
10. startDate
11. Methods
12. noSuchMethod
13. split
14. toString
15. Operators
16. operator ==