How can I FORCE a user to check-in a file(s)

I would like to require user's who check out files to check them back in.

Is there any to force a user to check in a file?

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Ideally the user would be prompted or required to check-in when the project is closed. I need to simulate the use of the check-in all button. this is because we have multiple user's using the project but sometimes individuals forget to hit the button to check in the commonly used files thus cause other people to wait.