deserializer._readHostObject()

调用此方法来读取某种宿主对象，即由原生 C++ 绑定创建的对象。 如果无法反序列化数据，则应抛出合适的异常。

此方法不存在于 Deserializer 类本身，但可以由子类提供。

This method is called to read some kind of host object, i.e. an object that is created by native C++ bindings. If it is not possible to deserialize the data, a suitable exception should be thrown.

This method is not present on the Deserializer class itself but can be provided by subclasses.