使用JMS序列化器反序列化XML，获得空对象

我正在尝试对以下XML进行反序列化:

<?xml version="1.0" encoding="utf-8"?>
<customers>
   <customer>
      <name>..</name>
      <address>..</address>
      <email>..</email>
      <website>..</website>
   </customer>
   <customer>
      ...
   </customer>
<customers>

我创建了以下实体:

use JMS'Serializer'Annotation as JMS;    
class customers
{
    public function __construct()
    {
        $this->customers = new ArrayCollection();
    }
    /**
    * @JMS'Type("ArrayCollection<MyBundle'Entity'customer>")
    * @JMS'XmlList(entry="customer")
    */
    public $customers;
}

这是第二个实体:

use JMS'Serializer'Annotation as JMS;    
class customer
{
    /**
    * @JMS'Type("string")
    */
    public $name;
    /**
    * @JMS'Type("string")
    */
    public $address;
    /**
    * @JMS'Type("string")
    */
    public $email;
    /**
    * @JMS'Type("string")
    */
    public $website;
}

然后在控制器中使用以下代码进行序列化:

$serializer = $this->get('jms_serializer');
$customers = $serializer->deserialize($inputStr, 'MyBundle'Entity'customers', 'xml');

只有对象一直为空?