Want to write tests for thsese methods in Java

package towerOfHanoi;

import java.util.Observable;

public class HanoiSolver extends Observable {

private Tower left;

private Tower middle;

private Tower right;

private int numDiscs;

public HanoiSolver(int numDiscs) {

left = new Tower();

middle = new Tower();

right = new Tower();

this.numDiscs = numDiscs;

}

public Tower getTower(Position pos) {

switch (pos) {

case LEFT:

return left;

case RIGHT:

return right;

case MIDDLE:

return middle;

default:

return left;

}

}

public int numDiscs() {

return numDiscs;

}

/**

*

*

*/

public void move(Tower source, Tower destination) {

destination.push(source.pop());

setChanged();

notifyObservers(destination.postion());

}

/**

*

*/

public void solveTowers(

int currentDiscs,

Tower startPole,

Tower tempPole,

Tower endPole) {

if (currentDiscs == 1) {

move(startPole, endPole);

}

else {

solveTowers(currentDiscs - 1, startPole, endPole, tempPole);

move(startPole, endPole);

solveTowers(currentDiscs - 1, endPole, tempPole, startPole);

}

}

/**

*

*/

public void solve() {

solveTowers(numDiscs, left, middle, right);

}

}