APISecurityScheme.empty constructor Null safety

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

APISecurityScheme class

1. Constructors
2. APISecurityScheme
3. apiKey
4. empty
5. http
6. oauth2
7. openID
8. Properties
9. castMap
10. connectURL
11. description
12. extensions
13. flows
14. format
15. hashCode
16. location
17. name
18. referenceURI
19. runtimeType
20. scheme
21. type
22. Methods
23. decode
24. encode
25. noSuchMethod
26. toString
27. Operators
28. operator ==