anchor.diff:    tells the Player to move right. updates the view if the model returns true
      */
     void moveRight() {
  -    String playerPos_old = ksModel.playerPositionAsString();
  -    if (ksModel.moveRight() == true) {
  -      List<String> crates_new = ksModel.crateList();
  -      String playerPos_new = ksModel.playerPositionAsString();
  -      updateView(playerPos_old, playerPos_new, crates_new);
  +    List<String> positions = ksModel.moveRight();
  +    if (positions.isEmpty == false) {
  +      String playerPos_old = positions.removeLast();
  +      String playerPos_new = positions.removeLast();
  +      updateView(playerPos_old, playerPos_new, positions);
       }
     }
   
  
positive.code:   tells the Player to move down. updates the view if the model returns true
     */
    void moveDown() {
      String playerPos_old = ksModel.playerPositionAsString();
      if (ksModel.moveDown() == true) {
        List<String> crates_new = ksModel.crateList();
        String playerPos_new = ksModel.playerPositionAsString();
        updateView(playerPos_old, playerPos_new, crates_new);
      }
    }
  
  
negative.code:   tells the Player to move up. updates the view if the model returns true
     */
    void moveUp() {
      List<String> positions = ksModel.moveUp();
      if (positions.isEmpty == false) {
        String playerPos_old = positions.removeLast();
        String playerPos_new = positions.removeLast();
        updateView(playerPos_old, playerPos_new, positions);
      }
    }
  
  