anchor.diff:    Assert.IsFalse(TIsbn.isValid('3598215078X'));
   end;
   
  +procedure ISBNVerifierTest.too_short_isbn;
  +begin
  +  Assert.IsFalse(TIsbn.isValid('00'));
  +end;
  +
   procedure ISBNVerifierTest.valid_isbn_number;
   begin
     Assert.IsTrue(TIsbn.isValid('3-598-21508-8'));
  
positive.code:     [Test]
      [Ignore]
      procedure empty_ISBN;
    end;
  
  implementation
  
negative.code:   DUnitX.TestFramework;
  
  const
    CanonicalVersion = '2.6.0';
  
  type
    [TestFixture]
  