public void CreateMcLaurienSeries_Test()
        {
            var plotter = new Plotter();

            plotter.ProcessString("s(x)");

            BaseNode mcLaurien;

            plotter.CreateMcLaurienSeries(out mcLaurien, 3);

            var result   = plotter.ProcessTree(2, mcLaurien);
            var expected = 0.6666d;

            Assert.AreEqual(expected, result, 3);
        }