1. @override
void initialize(World world)

Called when the actor is instantiated in the world

Source 

@override
void initialize(World world)
{
    super.initialize(world);
    this.name = "Enemy" + world.genUID();
    this.onCozynessChange = _cozynessChangeEvent.stream.asBroadcastStream();

    new Observable( this.onCollide )
        .throttle( new Duration(milliseconds: 700) )
        .listen( (Actor a) => this._collided(a) );
}