A picky customer comes to a small food shop and sees a new delivery of fresh fruit. “Give me two kilograms of oranges and wrap every orange up in a separate piece of paper, please,” he says to the saleswoman. She does.

“And three kilograms of apples, please, and wrap up every one in a separate piece of paper, too.” She does.

“And what is that there,” he asks pointing out a bushel basket in the corner.

“Grapes,” says the saleswoman, “but they are not for sale!”