import 'package:angular2/core.dart'; @Injectable() class Engine { final int cylinders; Engine() : cylinders = 4; Engine.withCylinders(this.cylinders); } @Injectable() class Tires { String make = 'Flintstone'; String model = 'Square'; } @Injectable() class Car { //#docregion car-ctor final Engine engine; final Tires tires; String description = 'DI'; Car(this.engine, this.tires); // #enddocregion car-ctor // Method using the engine and tires String drive() => '$description car with ' '${engine.cylinders} cylinders and ' '${tires.make} tires.'; }