HttpManager constructor Null safety

1. baguette
2. HttpManager
3. HttpManager
4. HttpManager constructor

HttpManager class

1. Constructors
2. HttpManager
3. Properties
4. hashCode
5. runtimeType
6. Methods
7. addPlugin
8. cleanPlugins
9. getPlugin
10. noSuchMethod
11. removePlugin
12. request
13. requestMultipart
14. toString
15. Operators
16. operator ==
17. Constants
18. METHOD_DELETE
19. METHOD_GET
20. METHOD_PATCH
21. METHOD_POST
22. METHOD_PUT
23. STATUS_CODE_BAD_REQUEST
24. STATUS_CODE_NO_CONNECTIVITY
25. STATUS_CODE_NOT_FOUND
26. STATUS_CODE_OK
27. STATUS_CODE_TIMEOUT
28. STATUS_CODE_UNAUTHORIZED
29. TAG