Description constructor Null safety

1. Flutter
2. matcher
3. Description
4. Description constructor

Description class

1. Constructors
2. Description
3. Properties
4. hashCode
5. length
6. runtimeType
7. Methods
8. add
9. addAll
10. addDescriptionOf
11. noSuchMethod
12. replace
13. toString
14. Operators
15. operator ==