do
New in version 1.5: The do tag was added in Twig 1.5.
The do tag works exactly like the regular variable expression ({{ ...
}}) just that it doesn’t print anything:
{% do 1 + 2 %}
© 2009–2018 by the Twig Team
Licensed under the three clause BSD license.
The Twig logo is © 2010–2020 Symfony
https://twig.symfony.com/doc/1.x/tags/do.html