你的辅助方法是最干净的方法，IMO.如果您传入一个列表或一个数组，那么一段不道德的代码可能会对其进行转换并更改内容，从而在某些情况下导致奇怪的行为.您可以使用只读集合，但这可能涉及更多的包装.我认为您的解决方案非常简洁.

Your helper method is the cleanest way to do it, IMO. If you pass in a list or an array, then an unscrupulous piece of code could cast it and change the contents, leading to odd behaviour in some situations. You could use a read-only collection, but that's likely to involve even more wrapping. I think your solution is as neat as it gets.