public void TryGetAsText_Given4_ReturnFour()
 {
     if (NullabilityAttributesExamined.TryGetDigitAsText('4', out string?text))
     {
         Assert.AreEqual <string>("four", text);
     }
 }
        public void TryGetAsText_GivenX4X2_ReturnFourTwo()
        {
            Assert.AreEqual <string>("four-two",
                                     NullabilityAttributesExamined.TryGetDigitsAsText("X4X2"));

            Assert.AreEqual <string?>(null,
                                      NullabilityAttributesExamined.TryGetDigitsAsText(null));
        }
 public void TryGetAsText_GivenX_ReturnFalse()
 {
     Assert.IsFalse(NullabilityAttributesExamined.TryGetDigitAsText('X', out _));
 }