getToken abstract method Null safety

1. baguette
2. ITokenManager
3. ITokenManager
4. getToken abstract method

ITokenManager class

1. Constructors
2. ITokenManager
3. Properties
4. hashCode
5. runtimeType
6. Methods
7. addPlugin
8. cleanPlugins
9. getPlugin
10. getToken
11. noSuchMethod
12. removePlugin
13. setToken
14. toString
15. Operators
16. operator ==