// Start is called before the first frame update
    void Start()
    {
        Display      d1 = new Display(new StringDisplayImpl("Hello, Japan."));
        Display      d2 = new CountDisplay(new StringDisplayImpl("Hello, World."));
        CountDisplay d3 = new CountDisplay(new StringDisplayImpl("Hello, Universe."));

        d1.Singledisplay();
        d2.Singledisplay();
        d3.Singledisplay();
        d3.MultiDisplay(5);
    }