Form layout: Add wrapper to fieldset

Hi all,

I'm trying to add a wrapper for all form fields in a Kentico MVC form layout. In the documentation I see how I can add a wrapper for the <form> element <FormWrapperConfiguration> or even a wrapper than can be applied to every single field <RootConfiguration>. See below:

<FormWrapperConfiguration>
    <FORM>
        <RootConfiguration>
            <FORM_FIELD_X>
        </RootConfiguration>
        <RootConfiguration>
            <FORM_FIELD_Y>
        </RootConfiguration>
        ...
        <SUBMIT_BUTTON>
    </FORM>
</FormWrapperConfiguration>

However, I can't find how to add a wrapper to the fieldset.

For instance, if I would use that <RootConfiguration> to add a <li> wrapper for the single fields, how can I add the <ul> element that wraps the fieldset?

Thanks in advance.

Kind regards,

Gustavo