ChoiceUtils constructor Null safety

1. baguette
2. ChoiceUtils
3. ChoiceUtils
4. ChoiceUtils constructor

ChoiceUtils class

1. Constructors
2. ChoiceUtils
3. Properties
4. hashCode
5. runtimeType
6. Methods
7. noSuchMethod
8. toString
9. Operators
10. operator ==
11. Static methods
12. showChoice