PhpCss\Parser\Sequence::createPseudoElement PHP Method

    private function createPseudoElement($token)
    {
        $name = substr($token->content, 2);
        switch ($name) {
            case 'first-line':
            case 'first-letter':
            case 'after':
            case 'before':
                return new Ast\Selector\Simple\PseudoElement($name);
        }
        throw new PhpCss\Exception\UnknownPseudoElement($token);
    }