âAbbie Hoffman on the Yippies and the 1968 Democratic Convention. Officially founded by Abbie Hoffman and Jerry Rubin in January 1968, the Youth International Party, or Yippies, were a countercultural group that briefly gained fame as a part of American activism.
Stretch assignments are experiences that challenge and potentially broaden a personâs current capabilities; e.g., assignments that require someone to manage and negotiate change, exert influence over others, and build coalitions.
In the present case, the method Ellipse.stretchX alters the length of one of its axes in place. If Circle inherits from Ellipse, it must also have a method stretchX, but the result of this method would be to change a circle into something which is no longer a circle. The Circle class cannot simultaneously satisfy its own invariant and the behavioural requirements of the Ellipse.stretchX method.