Let's say you've recently remodeled the communal laundry room at the apartment building you own, and you realize you need to test the coin-operated washer and dryer. You're fresh out of quarters? Never fear! It takes just a minute or two to get that laundry machine revving.
You'd never do this to a machine you didn't own, of course--that would be highly illegal, and you would go down deservedly--but just in case you find yourself in the situation above, here's how to do it: