BluetoothDeviceType constructor Null safety

1. printersdk
2. printer_models
3. BluetoothDeviceType
4. BluetoothDeviceType const constructor

BluetoothDeviceType enum

1. Constructors
2. BluetoothDeviceType
3. fromProto
4. Values
5. unknown
6. classic
7. le
8. dual
9. Properties
10. hashCode
11. index
12. runtimeType
13. Methods
14. noSuchMethod
15. toProto
16. toString
17. Operators
18. operator ==
19. Constants
20. values