public IAddClassToTargetSyntax AddClass(string className)
        {
            if (String.IsNullOrEmpty(className))
            throw new ArgumentNullException("className");

              var commandBuilder = new AddClassCommandBuilder(this, className);
              return commandBuilder;
        }
        public IAddClassToTargetSyntax AddClasses(params string[] classNames)
        {
            if (!classNames.Any())
            throw new ArgumentNullException("classNames");
              if (classNames.Any(String.IsNullOrEmpty))
            throw new ArgumentNullException("classNames");

              var commandBuilder = new AddClassCommandBuilder(this, classNames);
              return commandBuilder;
        }