public void GroupOfUnitsShouldExecuteCommand()
        {
            var map        = new Map(5, 5);
            var collection = new UnitCollection()
            {
                new Units.Tractor(map, Orientation.North, new System.Drawing.Point(0, 0)),
                new Stoun(map, new System.Drawing.Point(1, 0)),
                new Wind(map)
            };

            collection.ExecuteCommand(new MoveForwardCommand());
            Assert.AreEqual(1, (collection.ElementAt(0) as Units.Tractor).PositionY);
            Assert.AreEqual(0, (collection.ElementAt(1) as Units.Stoun).PositionY);

            collection.ExecuteCommand(new TurnClockwiseCommand());
            Assert.AreEqual(Orientation.East, (collection.ElementAt(0) as Units.Tractor).Orientation);
            Assert.AreEqual(Orientation.East, (collection.ElementAt(2) as Units.Wind).Orientation);
        }