textSpan property Null safety

1. flutter_json_widgets
2. widget
3. RichText
4. textSpan property

RichText class

1. Constructors
2. RichText
3. fromJson
4. Properties
5. copyWith
6. hashCode
7. key
8. locale
9. maxLines
10. overflow
11. runtimeType
12. selectionColor
13. semanticsLabel
14. softWrap
15. strutStyle
16. style
17. textAlign
18. textDirection
19. textHeightBehavior
20. textScaleFactor
21. textSpan
22. textWidthBasis
23. Methods
24. map
25. mapOrNull
26. maybeMap
27. maybeWhen
28. noSuchMethod
29. toJson
30. toString
31. when
32. whenOrNull
33. Operators
34. operator ==