def parent_links_for(crumb)
      links = []
      while crumb = crumb.parent
        links.unshift *crumb.links
      end
      links
    end
def parent_links_for(crumb)
      links = []
      while crumb = crumb.parent
        links.unshift *crumb.links
      end
      links
    end
Returns parent links for the crumb.