module Middleman::Sitemap::Extensions::Traversal

def parent
  parts = path.split("/")
  parts.pop if path.include?(app.index_file)
  return nil if parts.length < 1
  parts.pop
  parts << app.index_file
  parent_path = "/" + parts.join("/")
  store.find_resource_by_destination_path(parent_path)
end