@Test
  public void addASingleOrderToTheOrders() {

    assertEquals(0, uut.findAll().size());

    uut.save(OrdersFixtures.standardOrder());

    assertEquals(1, uut.findAll().size());
  }
  @Test
  public void removeASingleOrder() {

    UUID key = UUID.randomUUID();

    uut = new OrdersMemoryRepository(Collections.singletonMap(key, OrdersFixtures.standardOrder()));

    assertEquals(1, uut.findAll().size());

    uut.delete(key);

    assertEquals(0, uut.findAll().size());
  }