public void RemoveAllShapes() { var c = new CompositeShape(); var rpoint1 = new Point(20, 20); var rpoint2 = new Point(30, 20); var rpoint3 = new Point(30, 30); var rpoint4 = new Point(20, 30); var rect = new Rectangle(rpoint1, rpoint2, rpoint3, rpoint4); c.Add(rect); var tpoint1 = new Point(0, 0); var tpoint2 = new Point(3, 0); var tpoint3 = new Point(0, 3); var triangle = new Triangle(tpoint1, tpoint2, tpoint3); c.Add(triangle); c.RemoveAllShapes(); Assert.AreEqual(0, c.Points.Count); Assert.AreEqual(0, c.thisShapesList.Count); }