IHttpResponseSucess constructor Null safety

1. nyxx
2. nyxx
3. IHttpResponseSucess
4. IHttpResponseSucess constructor

IHttpResponseSucess class

1. Constructors
2. IHttpResponseSucess
3. Properties
4. body
5. hashCode
6. headers
7. jsonBody
8. runtimeType
9. statusCode
10. Methods
11. noSuchMethod
12. toString
13. Operators
14. operator ==