Using icons with django-select2

I would like to set an icon in front of the selectable items in a multiple choice field I'm rendering with django-select2.

Per the documentation, it looks like I'll need to use templateResult, but not sure how in my case.

My HTML (simplified below) is rendered with django-crispy-forms and django-select2 as follows:

<form class="form-horizontal" method="post" >
    <link href="//cdnjs.cloudflare.com/ajax/libs/select2/4.0.3/css/select2.min.css" type="text/css" media="screen" rel="stylesheet" />
    <script type="text/javascript" src="//cdnjs.cloudflare.com/ajax/libs/select2/4.0.3/js/select2.min.js"></script>
    <script type="text/javascript" src="/static/django_select2/django_select2.js"></script>
    <label for="id_recipients" class="control-label col-lg-2 requiredField">Recipient(s)<span class="asteriskField">*</span> </label> 
    <select multiple="multiple" class="select2multiplewidget form-control django-select2" data-allow-clear="false" data-minimum-input-length="0" data-placeholder="Select one or more recipients" id="id_recipients" name="recipients">
        <optgroup label="Groups">
            <option value="group_6">Group 6</option>
            <option value="group_2">Group 2</option>
            <option value="group_8">Group 8</option>
        </optgroup>
    </select>
</form>

I thought I'd be able to use JS like on the Example page, with the below, but the function is never called.

$(".select2multiplewidget").select2({
    templateResult: formatState
});