BarGraphState constructor Null safety

1. farmershands
2. bar_graph
3. BarGraphState
4. BarGraphState constructor

BarGraphState class

1. Constructors
2. BarGraphState
3. Properties
4. context
5. hashCode
6. isScrollReachEnd
7. isScrollReachStart
8. mounted
9. runtimeType
10. scrollController
11. scrollReachEndTimer
12. scrollReachStartTimer
13. scrollState
14. widget
15. Methods
16. activate
17. build
18. deactivate
19. debugFillProperties
20. didChangeDependencies
21. didUpdateWidget
22. dispose
23. initState
24. noSuchMethod
25. reassemble
26. scrollListenerCallback
27. setState
28. toDiagnosticsNode
29. toString
30. toStringShort
31. Operators
32. operator ==