public void BadSudoku_IsValid_ReturnsFalse()
        {
            bool expected = false;

            bool actual = badSudoku.IsValid();

            Assert.That(actual, Is.EqualTo(expected));
        }
        public void GoodSudoku_IsValid_ReturnsTrue()
        {
            bool expected = true;

            bool actual = goodSudoku.IsValid();

            Assert.That(actual, Is.EqualTo(expected));
        }