构造函数将这些集合创建为不可修改的列表，使得它们可以安全地直接返回。

The constructor creates these collections as unmodifiable lists, making it safe to return them directly.

youdao

构造函数将这些集合创建为不可修改的列表，使得它们可以安全地直接返回。

The constructor creates these collections as unmodifiable lists, making it safe to return them directly.

youdao