有人在问答集( ^ ])提供了指向该网站的链接 ^ ]，我认为这可以帮助您实施.

Some one her at Q&A ( Design pattern for permissions[^] ) gave a link to this web site http://www.cs.sjsu.edu/~pearce/oom/patterns/analysis/Actor.htm[^], I think that this can help you in implementation.