Where is this Joker quote from?

"I've heard that joke before. That's the sign of a bad comedian. Comedians, see, they've got to be original. Otherwise the audience won't laugh, and he'll go home to his wife and kid and eat TV dinners instead of going out to eat, and talk about the weather and how sunny it is outside. Wifey will ask him why they're not at the restaurant they talked about, he'll eat his green beans, wifey will ask again, more insistent this time, and he'll smile real big and SHOOT THEM BOTH IN THE FACE!! Eat your vegetables, dear. Haha... trust me, I know a thing or three about comedians. You're not that funny to me. Not yet." -The Joker.