使用他们的全名，FooModule::User 和 ::User

Refer to them using their full names, FooModule::User and ::User

一般来说，如果你只使用 User，它应该假设你的意思是 ::User，除非你在 FooModule 中.无论哪种方式，请使用 FooModule::User 或 ::User 来确保.

Generally if you just use User, it should assume you mean ::User, unless you are within FooModule. Either way, use FooModule::User or ::User to be sure.