View file phpBB3/vendor/twig/twig/lib/Twig/Loader/Chain.php

<?php

use Twig\Loader\ChainLoader;

class_exists('Twig\Loader\ChainLoader');

@trigger_error('Using the "Twig_Loader_Chain" class is deprecated since Twig version 2.7, use "Twig\Loader\ChainLoader" instead.', \E_USER_DEPRECATED);

if (false) {
    /** @deprecated since Twig 2.7, use "Twig\Loader\ChainLoader" instead */
    class Twig_Loader_Chain extends ChainLoader
    {
    }
}