/usr/share/php/Symfony/Component/Security/Core/Authentication/Token/ is in php-symfony-security 2.7.10-0ubuntu2.
This file is owned by root:root, with mode 0o755.
..
/usr/share/php/Symfony/Component/Security/Core/Authentication/Token/AbstractToken.php
/usr/share/php/Symfony/Component/Security/Core/Authentication/Token/AnonymousToken.php
/usr/share/php/Symfony/Component/Security/Core/Authentication/Token/PreAuthenticatedToken.php
/usr/share/php/Symfony/Component/Security/Core/Authentication/Token/RememberMeToken.php
/usr/share/php/Symfony/Component/Security/Core/Authentication/Token/Storage/
/usr/share/php/Symfony/Component/Security/Core/Authentication/Token/Storage/TokenStorage.php
/usr/share/php/Symfony/Component/Security/Core/Authentication/Token/Storage/TokenStorageInterface.php
/usr/share/php/Symfony/Component/Security/Core/Authentication/Token/TokenInterface.php
/usr/share/php/Symfony/Component/Security/Core/Authentication/Token/UsernamePasswordToken.php