如何使用solarium创建字符串类型的solr文档

require 'vendor/autoload.php';
use Solarium\Client;

$client = new Solarium\Client([
    'endpoint' => [
        'localhost' => [
            'host' => '127.0.0.1',
            'port' => 8983,
            'path' => '/solr/',
        ]
    ]
]);

$doc = $client->createDocument();
$doc->id = 1; // 设置文档的唯一标识符
$doc->title = 'Example Title'; // 设置字符串类型的字段

$update = $client->createUpdate();
$update->addDocument($doc);

$result = $client->update($update);

if ($result->getStatus() == 0) {
    echo '文档提交成功';
} else {
    echo '文档提交失败';
}