Wrapper around block in Django template?

Question

Django

Good evening.
In the parent template, you need to insert a wrapper around the block defined in the child template, but if this block is not defined, then you do not need to insert a wrapper ( ). How can this be implemented? base.html:<div class="card stacked">...</div>

{% block content %}
    ...
    <div class="card stacked">
        <div class="card-body">
            {% block account_form %}{% endblock %}
         </div>
    </div>
    ...
{% endblock %}

login.html:

{% extends "account/base.html" %}

{% block account_form %}
    <form ...>
{% endblock %}