You will never instantiate this class directly, but always create an instance of its subclass.

永远不要直接实例化这个类，而是创建它的子类的一个实例。

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You never create an instance of it — instead, you always work with a subclass.

您永远不会创建它的实例——相反，您总是使用它的子类。

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In fact, InputStream is abstract, so some sort of subclass is necessary.

实际上，InputStream是一个抽象类，因此某种类型的子类是必要的。

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There is a subclass of the base message class specific to each type of message.

Message基类的一个子类特定于消息的具体类型。

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The root element of an MXML document is a subclass of the Application class.

一个MXML文档的根元素是application类的一个子类。

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The tree class represents a tree and is a subclass of Basetree.

树以tree类表示，这个类是Basetree的子类。

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As you can see, the FlickrView class is a subclass of ImageView.

可以看到，flickrview类是ImageView的子类。

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Create a mock object class as a subclass of the concrete class.

创建一个模拟对象类作为具体类中的一个子类。

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Now we can create our bean as a subclass of this.

现在，我们可以以这个类为父类创建子类bean。

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The first thing to do is create a subclass of the CaseFolder class definition.

首先，创建CaseFolder类的一个子类。

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Now, this is a lot of overhead just to subclass.

现在，这是一个很大的开销只是为了子类。

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The proxy class is an actual subclass of the persistent class.

实际上，代理类是持久化类的子类。

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The proxy class is an actual subclass of the persistent class.

实际上，代理类是持久化类的子类。

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