public void ChangeAngularUnit()
        {
            Assert.AreEqual(0, calculator.AngularUnit);

            calculator.ChangeAngularUnit();

            Assert.AreEqual(1, calculator.AngularUnit);

            calculator.ChangeAngularUnit();

            Assert.AreEqual(2, calculator.AngularUnit);

            calculator.ChangeAngularUnit();

            Assert.AreEqual(0, calculator.AngularUnit);
        }