问对象存储服务 PHP SDK查找Bucket不存在？

使用PHP SDK删除COS上文件，提示Bucket不存在

配置文件：

'cos' => [ 'region' => 'cn-sorth', 'fileBucket' => 'wafer', 'uploadFolder' => 'pic', 'appID' => '1256827978' ],

控制器：

Version:1.0 StartHTML:0000000128 EndHTML:0000004192 StartFragment:0000000128 EndFragment:0000004192 SourceURL:about:blank

$cosClient = Cos::getInstance();
$cosConfig = Conf::getCos();
$bucketName = $cosConfig['fileBucket'];
$appId = $cosConfig['appID'];
$bucket_name = $bucketName."-".$appId;

echo $bucket_name;
$result = $cosClient->listBuckets();
var_dump($result);

$b_result =  $cosClient->headBucket(array('Bucket' => $bucket_name));
var_dump($b_result);

$result = $cosClient->deleteObject(array(
    'Bucket' => $bucket_name,
    'Key' => $key));
return $result ;

echo $bucket_name;

输出：wafer-1256827978

$result = $cosClient->listBuckets();
var_dump($result);

输出：

object(Guzzle\Service\Resource\Model)#68 (2) {

["structure":protected]=>

NULL

["data":protected]=>

array(3) {

["Owner"]=>

array(2) {

["ID"]=>

string(43) "qcs::cam::uin/100005875745:uin/100005875745"

["DisplayName"]=>

string(12) "100005875745"

}

["Buckets"]=>

array(2) {

[0]=>

array(3) {

["Name"]=>

string(22) "nongjiayuan-1256827978"

["Location"]=>

string(10) "ap-beijing"

["CreationDate"]=>

string(20) "2018-06-08T01:53:20Z"

}

[1]=>

array(3) {

["Name"]=>

string(16) "wafer-1256827978"

["Location"]=>

string(12) "ap-guangzhou"

["CreationDate"]=>

string(20) "2018-06-08T05:47:06Z"

}

}

["RequestId"]=>

string(40) "NWIxYjc4N2RfYThhYjM1MGFfYjI4Ml8xNmQzOWY="

}

}

报错：

<h4>An uncaught Exception was encountered</h4>

<p>Type: Guzzle\Common\Exception\InvalidArgumentException</p>

<p>Message: Command was not found matching HeadBucket</p>

<p>Filename: /data/release/php-weapp-demo/vendor/guzzle/guzzle/src/Guzzle/Service/Client.php</p>

<p>Line Number: 87</p>

明明名字完全一样为什么还是找不到？？？？？