DATE_FORMAT property Null safety

1. baguette
2. DateTimeUtils
3. DateTimeUtils
4. DATE_FORMAT property

DateTimeUtils class

1. Constructors
2. DateTimeUtils
3. Properties
4. hashCode
5. runtimeType
6. Methods
7. noSuchMethod
8. toString
9. Operators
10. operator ==
11. Static properties
12. DATE_FORMAT
13. DATE_FORMAT_DAYS
14. DATE_FORMAT_DAYS_MONTH
15. Static methods
16. countDays
17. currentMillis
18. firstDay
19. getDays
20. getReadable
21. getReadableRange
22. lastDay
23. openDatePicker
24. openDateRangePicker
25. openMonthPicker