private World()
{
this.shuttles = new Dictionary<int, Shuttle>();
this.routes = new Dictionary<int, Route>();
this.stops = new Dictionary<string, Stop>();
this.Shuttles = this.shuttles.AsReadOnly<int, Shuttle>();
this.Routes = this.routes.AsReadOnly<int, Route>();
this.Stops = this.stops.AsReadOnly<string, Stop>();
}