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so a couple of months ago I created my own package. Everything in it works great, and so far it does everything I need it to do, the way I need it to. But I want to change one thing. When I made the package, I found it necessary to create a structure declaration in the package that says
Until now, I have been very happy with it. But I've decided (in order to separate the solutions from the surrounding text) that I want the structure to add a black square at the end every time the structure ends. Could somebody tell me how to modify my code to do this?