static void Main(string[] args)
{
// Create a jet plane
var jetEngine = new JetEngine();
var fokker = new Plane(jetEngine);
fokker.Start();
// Create a Propeller plane
var propellerEngine = new PropellerEngine();
var cessna = new Plane(propellerEngine);
cessna.Start();
}
static void Main(string[] args)
{
// Create a jet plane, the default
var fokker = new Plane();
fokker.Start();
// Create a Propeller plane
var cessna = new Plane();
var propellerEngine = new PropellerEngine();
cessna.Engine = propellerEngine;
cessna.Start();
}