单例对象被垃圾回收机制回收，然后单例类又被重新加载。

Singleton classes destroyed by garbage collection, then reloaded.

youdao

由于子类的实例也是单例类的实例，所以可能出现多个单例实例并存的情况。

Since an instance of a subclass is an instance of your superclass, you could find multiple instances of the singleton.

youdao

他们会发现每次他们要创建一个不同的单例类的时候，都不得不写同样得代码。

Those who use it will find that they often have to write the same code each time they want to create a different Singleton class.

youdao