public void Given_An_Integer_Should_Compute_IsDuoDigit(int number, int expected)
        {
            // arrange
            // act
            var isDuoDigit = IsDuoDigitKata.IsDuoDigit(number);

            // assert
            isDuoDigit.Should().Be(expected);
        }
 public int Solution()
 {
     return(IsDuoDigitKata.IsDuoDigit(_number));
 }