price property Null safety

1. fw_flutter_sdk
2. fw_flutter_sdk
3. ProductUnit
4. price property

ProductUnit class

1. Constructors
2. ProductUnit
3. Properties
4. hashCode
5. imageUrl
6. isAvailable
7. name
8. options
9. price
10. runtimeType
11. unitId
12. url
13. Methods
14. noSuchMethod
15. toString
16. Operators
17. operator ==