onResult property Null safety

1. baguette
2. CheckoutSecurityScreenWidget
3. CheckoutSecurityScreenWidget
4. onResult property

CheckoutSecurityScreenWidget class

1. Constructors
2. CheckoutSecurityScreenWidget
3. Properties
4. checkoutSecurity
5. data
6. hashCode
7. key
8. onResult
9. runtimeType
10. Methods
11. createElement
12. createState
13. debugDescribeChildren
14. debugFillProperties
15. getName
16. noSuchMethod
17. toDiagnosticsNode
18. toString
19. toStringDeep
20. toStringShallow
21. toStringShort
22. Operators
23. operator ==