public void PositionateAbsoluteEdgeWithNoLeft()
        {
            var edge = new OnTopEdge();

            edge.Add(null, null);
            edge.Positionate(WIDTH, HEIGHT);
        }
        public void PositionateAbsoluteOnTopEdge()
        {
            var edge = new OnTopEdge();

            edge.Add(this.Left, null);
            edge.Positionate(WIDTH, HEIGHT);

            Assert.IsNotNull(edge.Left.Position);
            Assert.AreEqual(edge.Left, this.Left);
            Assert.AreEqual(edge.Left.Position.Value.Y, 0);
        }