{% macro form(action='', class=none, id=none) %}
<form method="post" action="{{action}}" {{ {'id': id, 'class': class}|xmlattr }} {{kwargs|xmlattr}} >
    {% if csrf_token is defined %}
        <input type="hidden" name="csrf_token" value="{{csrf_token}}">
    {% endif %}
    {{ caller() }}
</form>
{% endmacro %}