public void CreatePositive(string targetDirectory)
        {
            var created = DirectoryCreator.CreateWithTimeMark(targetDirectory);

            _directory = targetDirectory;
            Assert.IsTrue(Directory.Exists(created), "Directory doesn't exist");
        }
 public void CreateNegative(string targetDirectory)
 {
     Assert.That(() => { DirectoryCreator.CreateWithTimeMark(targetDirectory); },
                 Throws.Exception);
 }