/** Test method for {@link commons.Position#clone()}. */
public void testClone() {
Position clone = position.clone();
assert position.x() == clone.x() && position.y() == clone.y();
clone.add(new Position(1, 2));
assert position.x() != clone.x() && position.y() != clone.y();
}
/** Test method for {@link commons.Position#add(commons.Position)}. */
public void testAdd() {
position.add(new Position(5, 7));
assert position.x() == 6 && position.y() == 9;
}