{% set headers = kwargs.get("headers") %}
{% if headers %}
{{ key(headers,  **kwargs) }}: {{ value(headers, **kwargs) }}
{% endif %}
<ul>
    {% for item in obj%}
    <li>{{ key(item, loop.index, **kwargs)|safe }} {{ sep(item, **kwargs)|safe }} {{ value(item, **kwargs)|safe }}</li>
    {% endfor%}
</ul>