APITag.empty constructor Null safety

1. conduit_open_api
2. open_api_v3
3. APITag
4. APITag.empty constructor

APITag class

1. Constructors
2. APITag
3. empty
4. Properties
5. castMap
6. description
7. extensions
8. hashCode
9. name
10. referenceURI
11. runtimeType
12. Methods
13. decode
14. encode
15. noSuchMethod
16. toString
17. Operators
18. operator ==