An Example of Stepwise Refinement(BanishWinter)

import stanford.karel.*;


public class BanishWinter extends SuperKarel {


public void run() {
while (beepersInBag()) {
moveToTree();
climbTree();
putDownBeeper();
toBottom();
}
}


private void moveToTree() {
while (frontIsClear())
move();
}


private void climbTree() {
while (frontIsBlocked()) {
turnLeft();
move();
turnRight();
}
}


private void putDownBeeper() {
turnLeft();
putTwoBeeper();
turnRight();
move();
turnRight();
putTwoBeeper();
}


private void putTwoBeeper() {
putBeeper();
move();
putBeeper();
}


private void toBottom() {
while (frontIsClear())
move();
turnLeft();
}


}