# File lib/sass/selector/pseudo.rb, line 116
      def to_s
        res = (syntactic_type == :class ? ":" : "::") + @name
        if @arg || @selector
          res << "("
          res << @arg.strip if @arg
          res << " " if @arg && @selector
          res << @selector.to_s if @selector
          res << ")"
        end
        res
      end