I have just started working with nodejs. I wonder if there is a way to require a file only once in an app. I am using a class framework for getting classic OOPS in my JS project. Each class is contained in its own JS file. I want to require the class framework in each file so that they can function independently but want the framework's init code to be executed only once.

I can use a flag to implement this myself but a built-in way would be nice. Search for require once leads me to all PHP related questions.