OutOfBandOperation constructor Null safety

1. nevis_mobile_authentication_sdk
2. nevis_mobile_authentication_sdk
3. OutOfBandOperation
4. OutOfBandOperation constructor

OutOfBandOperation class

1. Constructors
2. OutOfBandOperation
3. Properties
4. hashCode
5. runtimeType
6. Methods
7. execute
8. noSuchMethod
9. onAuthentication
10. onError
11. onRegistration
12. payload
13. requestHeaders
14. toString
15. Operators
16. operator ==