<div class="form-group">
    {% if field.label %}
        <label {% if field.style.hide_label %}class="sr-only"{% endif %}>{{ field.label }}</label>
    {% endif %}
    <select multiple class="form-control" name="{{ field.name }}">
        {% for key, text in field.choices.items %}
        <option value="{{ key }}" {% if key in field.value %}selected{% endif %}>{{ text }}</option>
        {% endfor %}
    </select>
</div>
