What popular agile development method names its participants after the characters found in the following story, first told by Bennett Cerf on June 13, 1950 and published in the Titusville, Pennsylvania Herald in the column “Try and Stop Me?”

A hen and a pig were sauntering down the main street of an Indiana town when they passed a restaurant that advertised “Delicious ham and eggs: 75¢.”

“Sounds like a bargain,” approved the hen. “That owner obviously knows how to run his business.”

“It’s all very well for you to be so pleased about the dish in question,” observed the pig with some resentment. “For you it is all in the day’s work. Let me point out, however, that on my part it represents a genuine sacrifice.”