亚马逊s3删除功能在PHP无法正常工作

I want to delete a specific object from my bucket. I used this code for deleting. But this not working for me.

    use Aws\S3\S3Client;
$s3 = S3Client::factory(array(
    'key'    => CONTENT_KEY,
    'secret' => CONTENT_SECRET
));
$keyname     = "/".CONTENT_PATH."/magazinename";


if ($s3->deleteObject(CONTENT_BUCKET, $keyname)) {
echo "Deleted file.";
}

I got an error that:

Catchable fatal error: Argument 2 passed to Guzzle\Service\Client::getCommand() must be an array

$bucket = '*** Your Bucket Name ***';
$keyname = '*** Your Object Key ***';

$result = $s3->deleteObject(array(
'Bucket' => $bucket,
'Key'    => $keyname));

http://docs.aws.amazon.com/AmazonS3/latest/dev/DeletingOneObjectUsingPHPSDK.html