ds-8.x-3.9/tests/themes/ds_test_layout_theme/templates/ds-test-layout-theme.html.twig

<{{ outer_wrapper }} class="test-template-defined-in-theme-class">
  <{{ ds_content_wrapper }} class="ds-content-wrapper">
    {{ ds_content }}
  </{{ ds_content_wrapper }}>
</{{ outer_wrapper }}>