brightness property Null safety

1. Flutter
2. material
3. ColorScheme
4. brightness property

ColorScheme class

1. Constructors
2. ColorScheme
3. dark
4. fromSeed
5. fromSwatch
6. highContrastDark
7. highContrastLight
8. light
9. Properties
10. background
11. brightness
12. error
13. errorContainer
14. hashCode
15. inversePrimary
16. inverseSurface
17. onBackground
18. onError
19. onErrorContainer
20. onInverseSurface
21. onPrimary
22. onPrimaryContainer
23. onSecondary
24. onSecondaryContainer
25. onSurface
26. onSurfaceVariant
27. onTertiary
28. onTertiaryContainer
29. outline
30. primary
31. primaryContainer
32. primaryVariant
33. runtimeType
34. secondary
35. secondaryContainer
36. secondaryVariant
37. shadow
38. surface
39. surfaceTint
40. surfaceVariant
41. tertiary
42. tertiaryContainer
43. Methods
44. copyWith
45. debugFillProperties
46. noSuchMethod
47. toDiagnosticsNode
48. toString
49. toStringShort
50. Operators
51. operator ==
52. Static methods
53. lerp