Because clone has protected access in Object and, to call clone , you have to call it through a reference to a class that has overridden clone to be public.

因为clone在Object中是保护访问的，调用clone必须通过将clone改写公共访问的类引用来完成。

youdao

Be sure your script is protected from an error; if the method call fails, it throws an exception.

要确保脚本能够应对错误；如果方法调用失败，它会抛出异常。

youdao

The method is protected, so the test can't call it directly.

这个方法是protected的方法，所以测试不能直接调用它。

youdao

Most of the communications companies using GE-3 have "protected contracts, " which call for GE Americom to move their signals to other satellites, the company said.

CNN: graphic

Ok, then what about the code that enables video call support in OS 3.2 or that protected engineering prototype we saw just one day before launch showing a cutout at precisely the same spot so as to not obscure whatever was underneath?

ENGADGET: Apple iPad rumor roundup: Abraham Zapruder edition

Location data gathered by the phones we call carry around every day is also not well protected by ECPA. While the Fourth Amendment law gives warrant protection against location information collected through a physical trespass, that limitation is weak since other tools can be used to avoid such legal hurdles.

FORBES: Lawmakers Propose Changes To Make Government Get Warrant Before Reading Your Email