public void Add_ShouldAddTargetedInstanceInCollection() { AbstractShape expectedShape = new Square("SqareName", 44); ShapeCollection actualShapeCollection = new ShapeCollection(); actualShapeCollection.Add(expectedShape); Assert.AreEqual(1, actualShapeCollection.Count); Assert.AreEqual(expectedShape.Name, actualShapeCollection.Single <AbstractShape>().Name); Assert.AreEqual(expectedShape.Surface, actualShapeCollection.Single <AbstractShape>().Surface); }