# File lib/scruffy/formatters.rb, line 31
    def route_format(target, idx, options = {})
      args = [target, idx, options]
      if respond_to?(:format)
        send :format, *args[0...self.method(:format).arity]
      elsif respond_to?(:format!)
        send :format!, *args[0...self.method(:format!).arity]
        target
      else
        raise NameError, "Formatter subclass must container either a format() method or format!() method."
      end
    end