Learning_GTK4_tree/testsuite/gtk/ui/dialog4.ui

<!-- invalid dialog markup element -->
<interface>
  <object class="GtkDialog">
    <child type="action">
      <object class="GtkButton" id="button_ok">
      </object>
    </child>
    <action-widgets>
      <warbl/>
    </action-widgets>
  </object>
</interface>