Where should I put CONTROLLER helper methods?

I know that "helpers" are usually for views/templates. But say I have a helper method that I want to call from different controllers. Where should this file go?

I was thinking 开发者_开发技巧of creating a helper module in the "models" folder but I'd like to know if there's a "correct" way to do this.

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Any method you put in ApplicationController will be inherited by your other controllers (as long as it's not private of course).