private void swapWithEmpty(int[][] newLayout, int destX, int destY) {
   newLayout[(int) emptySpace.getY()][(int) emptySpace.getX()] = newLayout[destY][destX];
   newLayout[destY][destX] = EMPTY_SPACE;
 }
 private boolean canSlideUp() {
   return emptySpace.getY() != (n - 1);
 }
 private NPuzzleState slideLeft() {
   int[][] copyOfLayout = TwoDArrayUtils.makeCopy(layout);
   swapWithEmpty(copyOfLayout, (int) emptySpace.getX() + 1, (int) emptySpace.getY());
   return new NPuzzleState(copyOfLayout, n);
 }
 private boolean canSlideDown() {
   return emptySpace.getY() != 0;
 }