This was already cast as the correct class of product object, so you do not need to cast it yourself.

这时产品对象已经被转换成为了正确的类，所以您不需要自己再次的转换它。

youdao

This specification applies to one class of product: content delivered to a mobile device, including the metadata transferred as part of the delivery protocol.

本规范适用与一类产品：传输到移动设备的内容，包括传输协议中被传输的数据。

youdao

Oncology injectable medicines are a highly specialized class of product and are difficult to produce due to their toxic characteristics and need for special preparation and handling.

肿瘤注射药物是一类产品的高度专业化，而且难以产生，由于其毒性的特点和需要特殊的准备和处理。

youdao

New markets seldom get built this way, unless the consumer experience is so compelling and the brand so powerful that people will consider a totally new class of product (see the iPad, which demonstrates just how high a bar those criteria are to meet).

FORBES: Is Google Too Rushed to Pioneer?

The depth and class of the apple product is just too deep.

FORBES: The Most Important Question Facing Apple's New iPad Mini

"Lufthansa has invested quite a bit of money in keeping a first-class product because a lot of airlines are moving out of first-class where there is not enough traffic to warrant it, " says Buckenburg.

CNN: First-class vs. business: Is it worth the extra cost?