need fromJson with Type

e.g. I have a nullable list ['text', null] and write a safe conversion
```
@JsonKey(fromJson: safeList)
List property;
```
```
List safeList(dynamic value, {List defaultValue = const []}) =>
safeNullableList(value) ?? defaultValue;

List? safeNullableList(dynamic value) {
if (value is List) return value;
if (value is List) return value.whereType().toList();
return null;
}
```