Edit File: IntegrationTestCase.php
<?php use Twig\Test\IntegrationTestCase; class_exists('Twig\Test\IntegrationTestCase'); @trigger_error(sprintf('Using the "Twig_Test_IntegrationTestCase" class is deprecated since Twig version 2.7, use "Twig\Test\IntegrationTestCase" instead.'), E_USER_DEPRECATED); if (\false) { /** @deprecated since Twig 2.7, use "Twig\Test\IntegrationTestCase" instead */ class Twig_Test_IntegrationTestCase extends IntegrationTestCase { } }