{
    "top_level": [
        {
            "children": [
                {
                    "children": []
                },
                {
                    "children": []
                }
            ]
        },
        {
            "children": [
                {
                    "children": []
                }
            ]
        }
    ]
}
---
{%- macro nest(children) -%}
    <nest>
    {%- for child in children -%}
        <child>{{ nest(child.children) }}</child>
    {%- endfor -%}
    </nest>
{%- endmacro -%}
{% set not_nest = nest %}
{{ not_nest(top_level) }}
