Multiple blocks of same name in Jinja2

As documented here, defining a block creates a macro with the name of the block in the special "self" object:

<title>{% block title %}{% endblock %} - example.com</title>
[...]

<h1> 
  {{ self.title() }} - example.com
</h1>

The idea is to create a block inside a macro and then call macro two times, instead of having "block" tag repeated twice.

In latest Jinja2 version this works:

layout.html

{%- extends "base.html" -%}

{%- macro duplicated() -%}
    {% block overrideninchild %}{% endblock %}
{%- endmacro -%}

{% block base_content %}
    {{ duplicated() }}
    {{ duplicated() }}
{% endblock %}

child_page.html

{%- extends "layout.html" -%}

{% block overrideninchild %}
   Should be visible twice.
{% endblock %}