anchor.diff:    Assert.AreEqual(false, TLuhn.Valid('059a'));
   end;
   
  -procedure TLuhnTest.valid_strings_with_a_non_digit_included_become_invalid;
  +procedure TLuhnTest.using_ascii_value_for_non_doubled_non_digit_is_not_allowed;
   begin
     Assert.AreEqual(false, TLuhn.Valid('055a 444 285'));
   end;
  
positive.code: 
      [Test]
      [Ignore]
      procedure valid_strings_with_a_non_digit_included_become_invalid;
  
      [Test]
      [Ignore]
      procedure valid_strings_with_a_non_digit_added_at_the_end_become_invalid;
  
      [Test]
  
negative.code:   Assert.AreEqual(false, TLuhn.Valid(' 0'));
  end;
  
  procedure TLuhnTest.using_ascii_value_for_doubled_non_digit_is_not_allowed;
  begin
    Assert.AreEqual(false, TLuhn.Valid(':9'));
  end;
  