Symfony2 YML Bundle不包含任何映射实体

Question

我正在尝试使用src/Ibw/TazJazBundle/Resources/config/doctrine文件夹中的YML文件首次设置我的数据库。文件名为Customer.yml，内容如下：

IbwTazJazBundleEntityCustomer:
    type: entity
    table: customer
    id:
        id:
            type: integer
            generator: { strategy: AUTO }
    fields:
        customer_firstname:
            type: string
            length: 255
            required: true
        customer_lastname:
            type: string
            length: 255
            required: true
        customer_username:
            type: string
            length: 255
            required: true
        customer_password:
            type: string
            length: 255
            required: true
        customer_email:
            type: string
            length: 255
            required: true

当我运行命令php app/console doctrine:generate:entities IbwTazJazBundle时，收到错误消息[RuntimeException] Bundle "IbwTazJazBundle" does not contain any mapped entities

我不确定我做错了什么。请帮忙。谢谢！