public void TestPotential()
        {
            var thickness = Length.FromNanometers(10);
            var metal     = new Metal(thickness);

            metal.SetWorkFunction(Energy.FromElectronVolts(5));

            var expectedPotential = ElectricPotential.Zero;

            var actualPotential = metal.GetPotential(thickness);

            Assert.AreEqual(expectedPotential, actualPotential);
        }