@Test
 public void testGetStock() {
   testArrayStock.add(testStock);
   testArrayStock.add(testStock2);
   stockManager.persistStock(testArrayStock);
   testArrayStock2 = stockManager.getStock();
   assertEquals(stockManager.getStock(), testArrayStock2);
 }
 @Test
 public void testUpdateStock() {
   testArrayStock.add(testStock);
   stockManager.persistStock(testArrayStock);
   stockManager.updateStock(testStock);
   assertEquals(stockManager.getStock(), testArrayStock);
 }
 @Test
 public void testPersistStock() {
   stockManager.persistStock(testStock);
   testArrayStock = stockManager.getStock();
   assertEquals(testArrayStock.size(), 1);
 }