@Test
public void testIsSpaceAvailableSimple() {
Model m = new Model(10,10,0,0,0); // 10 by 10 pond with no obstacles, no fish, no plants
Fish f = new Fish(1, 7, 100, Fish.UP);
Plant p = new Plant(2, 8, 100);
m.addFish(f);
m.addPlant(p);
assertFalse(m.isSpaceAvailable(1, 7)); // there is a fish there
assertFalse(m.isSpaceAvailable(2, 8)); // there is a plant there
assertFalse(m.isSpaceAvailable(0, 0)); // there is a rock there (on the edge of pond)
}