QA Tester walks into a bar:

He orders a beer.
He orders 3 beers.
He orders 2976412836 beers.
He orders 0 beers.
He orders -1 beer.
He orders q beers.
He orders nothing.
Él ordena una cerveza.
Il commande une bière.
He orders a deer.
He tries to leave without paying.
He starts ordering a beer, then throws himself through the window half way through.
He orders a beer, gets his receipt, then tries to go back.
He orders a beer, goes to the door of the bar, throws a handful of cookies into the street, then goes back to the bar to see if the barmaid still recognizes him.
He orders a beer, and watches very carefully while the barmaid puts his order into the till to make sure nothing in his request got lost along the way.
He starts ordering a beer, and tries to talk the barmaid into handing over her personal details.
He orders a beer, sneaks into the back, turns off the power to the till, and waits to see how the barmaid reacts, and what she says to him.
He orders a beer while calling in thousands of robots to order a beer at exactly the same time.