public void Alternately_ThrowingExceptionOnNegativeInput(int n)
        {
            // Arrange

            // Act & Assert
            Assert.Throws(typeof(OmEnOmNegativeValueException), () => Alternately.AlternatelyRecursive(n));
        }
        public void AlternatelyTest(int n, long expected)
        {
            int actual;

            // Arrange

            // Act
            actual = Alternately.AlternatelyRecursive(n);

            // Assert
            Assert.AreEqual(expected, actual);
        }