specialText property Null safety

1. jrpn
2. view.buttons
3. CalculatorOnSpecialButton
4. specialText property

CalculatorOnSpecialButton class

1. Constructors
2. CalculatorOnSpecialButton
3. Properties
4. acceleratorKey
5. acceleratorLabel
6. bFactory
7. fKey
8. fText
9. gKey
10. gText
11. gTextOffset
12. hashCode
13. height
14. innerBorder
15. innerBorderColor
16. key
17. keyTextOffset
18. keyTextStyle
19. lowerSurface
20. lowerSurfaceColor
21. lowerSurfaceColorPressed
22. outerBorder
23. outerBorderPressedScale
24. runtimeType
25. specialText
26. uKey
27. upperSurface
28. upperSurfaceColor
29. upperSurfaceColorPressed
30. uText
31. width
32. Methods
33. createElement
34. createState
35. debugDescribeChildren
36. debugFillProperties
37. drawBlueText
38. drawCustomWhiteText
39. drawGoldText
40. drawKeyboardAccelerator
41. drawText
42. drawWhiteText
43. noSuchMethod
44. paintForPainter
45. toDiagnosticsNode
46. toString
47. toStringDeep
48. toStringShallow
49. toStringShort
50. Operators
51. operator ==