def parent_breadcrumb(options = {}, &block)
      if block_given?
        gretel_renderer.yield_parent_breadcrumb(options, &block)
      else
        gretel_renderer.parent_breadcrumb(options)
      end
    end
def parent_breadcrumb(options = {}, &block)
      if block_given?
        gretel_renderer.yield_parent_breadcrumb(options, &block)
      else
        gretel_renderer.parent_breadcrumb(options)
      end
    end
Returns or yields parent breadcrumb (second-to-last in the trail) if it is present.

   <% parent_breadcrumb do |link| %>
     <%= link_to link.text, link.url %> (<%= link.key %>)
   <% end %>