structuredAttrs is enabled

trying https://registry.npmjs.org/hast-util-classnames/-/hast-util-classnames-3.0.0.tgz
  % Total    % Received % Xferd  Average Speed  Time    Time    Time   Current
                                 Dload  Upload  Total   Spent   Left   Speed
100   5140 100   5140   0      0 99.43k      0                              0