Singleton classes destroyed by garbage collection, then reloaded.

单例对象被垃圾回收机制回收，然后单例类又被重新加载。

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Jeremy believes that most programmers don't use Ruby's objects right, so his talk sheds some light onto advanced topics like singleton classes and the instance_eval.

Jeremy认为大多数开发者都没有正确的使用Ruby对象，所以他的话题比较高阶，谈论了诸如单例类(singleton classes)和instance_eval。

youdao

This class provides a set of classes, or a set of singleton object instances, that include all of the root-level resources and providers (classes annotated with @Provider) in a JAX-RS application.

此类提供了一组类或一组单例（singleton）对象实例，在一个 JAX-RS 应用程序内包括所有的 根级别的资源和提供程序（由 @Provider 注释的类）。

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