webman使用的Twig模版引擎如何自定义分隔符？

$loader = new \Twig\Loader\ArrayLoader(['index' => '{[ name ]}',]);
$environment = new \Twig\Environment($loader);
$lexer = new \Twig\Lexer($environment, ['tag_variable' => ['{[', ']}']]);
$environment->setLexer($lexer);
$result = $environment->render('index', ['name' => 'Hello, world!']);
echo $result; // Hello, world!