It's more complicated code that requires extending a class to register an event listener.

它是更为复杂的代码，要求扩展类才能注册事件侦听程序。

youdao

As you can see, though, it takes a lot more to implement the Iterable interface manually than simply extending a class that does this work for you.

但是，您可以看到，与扩展一个现成的类来完成同样的工作相比，手动实现Iterable接口需要做的工作多得多。

youdao

It actually does a fair amount for the middle class, extending the Bush tax cuts and child tax credits and exemptions that benefit the middle class.

NPR: Political Ads May Not Tell Whole Story

President Obama also proposed extending tax cuts to protect middle class families and virtually every small business owner from getting a tax increase at the beginning of next year.

WHITEHOUSE: Advance Estimate of GDP for the Third Quarter of 2012

Extending this longstanding agreement reflects both companies' commitment to iDEN technology as a best-in-class platform for push-to-talk (PTT) services.

ENGADGET: Sprint inks another three years' worth of iDEN infrastructure support with Motorola, 'several' new phones coming in Q1