src/templates/bootstrap/fieldset.js

export default {
  form: `
<fieldset>
  {% if (component.legend) { %}
  <legend ref="header" class="{{component.collapsible ? 'formio-clickable' : ''}}">{{t(component.legend)}}</legend>
  {% } %}
  {% if (!collapsed) { %}
  <div class="fieldset-body" ref="{{nestedKey}}">
    {{children}}
  </div>
  {% } %}
</fieldset>
`,
};