using System.Collections.Generic;

class Test
{
    public interface IDrawable
    {
        void Draw();
    }

    public class Shape : IDrawable
    {
        public void Draw() {}
    }

    public void DrawItems(List<IDrawable> itemsToDraw) {}

    public Test()
    {
        List<Shape> shapes = new List<Shape>();
        DrawItems(shapes);
    }
}