def stylesheet(*urls)
      urls << {} unless urls.last.respond_to? :to_hash
      urls.last[:type] ||= mime_type(:css)
      link(:stylesheet, *urls)
    end
def stylesheet(*urls)
      urls << {} unless urls.last.respond_to? :to_hash
      urls.last[:type] ||= mime_type(:css)
      link(:stylesheet, *urls)
    end
Sets Link HTTP header and returns HTML tags for using stylesheets.