def tree(root_depth: 1, sitemap: false, nav_class: 'tree')
      return if m.parent_at_depth(root_depth).nil?
      @sitemap = sitemap
      h.content_tag :nav, class: nav_class do
        h.concat render_tree_master_ul(m.parent_at_depth(root_depth))
      end
    end
def tree(root_depth: 1, sitemap: false, nav_class: 'tree')
      return if m.parent_at_depth(root_depth).nil?
      @sitemap = sitemap
      h.content_tag :nav, class: nav_class do
        h.concat render_tree_master_ul(m.parent_at_depth(root_depth))
      end
    end
build page tree from specified root_depth, default second level root with sitemap property to render a sitemap from top root of current page