>>>
class VeryInterestingThing {
  factory VeryInterestingThing.fromJson(
        mylibrarythathasalongname.JsonData jsonData) => new VeryInterestingThing(
        otherlibrary.InterestingState.fromJson(jsonData.encodedState));
}
<<<
class VeryInterestingThing {
  factory VeryInterestingThing.fromJson(
          mylibrarythathasalongname.JsonData jsonData) =>
      new VeryInterestingThing(
          otherlibrary.InterestingState.fromJson(jsonData.encodedState));
}