def renderer_instance(options)
      return renderer.new(options) unless options[:renderer]

      if options[:renderer].is_a?(Symbol)
        registered_renderer = SimpleNavigation.registered_renderers[options[:renderer]]
        registered_renderer.new(options)
      else
        options[:renderer].new(options)
      end
    end
def renderer_instance(options)
      return renderer.new(options) unless options[:renderer]

      if options[:renderer].is_a?(Symbol)
        registered_renderer = SimpleNavigation.registered_renderers[options[:renderer]]
        registered_renderer.new(options)
      else
        options[:renderer].new(options)
      end
    end
FIXME: raise an exception if :rederer is a symbol and it is not registred
        in SimpleNavigation.registered_renderers