Is there a way to use the map type adapter on a nested class using toJson?

For example, if we were to have a class such as:

```dart
class Dog {
String name;
Trait trait
}

class Trait {
String traitName;
TraitAction action;
Map toJson() => ....
Trait.fromJson(...);
}
```

Would it be possible to create a type adapter for Dog that converts the nested trait object into json rather than having to create a new type adapter for the trait class?