def missing_diff_tree(locale, compared_to = base_locale)
      data[compared_to].select_keys do |key, _node|
        locale_key_missing? locale, depluralize_key(key, compared_to)
      end.set_root_key!(locale, type: :missing_diff).keys do |_key, node|
        # change path and locale to base
        data = { locale: locale, missing_diff_locale: node.data[:locale] }
        if node.data.key?(:path)
          data[:path] = LocalePathname.replace_locale(node.data[:path], node.data[:locale], locale)
        end
        node.data.update data
      end
    end
def missing_diff_tree(locale, compared_to = base_locale)
      data[compared_to].select_keys do |key, _node|
        locale_key_missing? locale, depluralize_key(key, compared_to)
      end.set_root_key!(locale, type: :missing_diff).keys do |_key, node|
        # change path and locale to base
        data = { locale: locale, missing_diff_locale: node.data[:locale] }
        if node.data.key?(:path)
          data[:path] = LocalePathname.replace_locale(node.data[:path], node.data[:locale], locale)
        end
        node.data.update data
      end
    end
keys present in compared_to, but not in locale