Annotations constructor Null safety

1. spine_client
2. annotations.pb
3. Annotations
4. Annotations constructor

Annotations class

1. Constructors
2. Annotations
3. Properties
4. hashCode
5. runtimeType
6. Methods
7. noSuchMethod
8. toString
9. Operators
10. operator ==
11. Static properties
12. http
13. Static methods
14. registerAllExtensions