{% extends "wagtailadmin/block_forms/sequence.html" %}
{% block header %}
    {% if list_members_html %}
        {% include "wagtailadmin/block_forms/stream_menu.html" with prefix=header_menu_prefix state="closed" %}
    {% else %}
        {% include "wagtailadmin/block_forms/stream_menu.html" with prefix=header_menu_prefix state="open" %}
    {% endif %}
{% endblock %}