@Test
  public void test4() {
    Layout l = new Layout();
    assertThat(l.getNumberOfItems(), equalTo(0));
    assertThat(l.getItems().size(), equalTo(0));

    Item item = new Item(ItemType.Triplet, new Cell(3, 2));
    l = l.addItem(item);

    assertThat(l.getNumberOfItems(), equalTo(1));
    assertThat(l.getIndex(item), equalTo(0));

    assertThat(l.getItem(new Cell(3, 1)), equalTo(item));
    assertThat(l.getItem(new Cell(3, 2)), equalTo(item));
    assertThat(l.getItem(new Cell(3, 3)), equalTo(item));
    assertThat(l.getItem(new Cell(3, 4)), nullValue());
    assertThat(l.getItem(new Cell(3, 0)), nullValue());

    l = l.moveItem(item, new Cell(6, 8));

    assertThat(l.getIndex(item), nullValue());
    item = l.getItems().get(0);
    assertThat(l.getItem(new Cell(6, 6)), nullValue());
    assertThat(l.getItem(new Cell(6, 7)), equalTo(item));
    assertThat(l.getItem(new Cell(6, 8)), equalTo(item));
    assertThat(l.getItem(new Cell(6, 9)), equalTo(item));
    assertThat(l.getItem(new Cell(6, 10)), nullValue());

    l = l.removeItem(new Item(ItemType.Triplet, new Cell(6, 8)));
    assertThat(l.getNumberOfItems(), equalTo(0));

    item = new Item(ItemType.Sun, new Cell(-4, -7));
    l = l.addItem(item);

    for (int row = -5; row <= -3; row++) {
      for (int col = -8; col <= -6; col++) {
        assertThat(l.getItem(new Cell(row, col)), equalTo(item));
      }
    }
    assertThat(l.getItem(new Cell(-2, -2)), nullValue());
  }
  @Test
  public void test3() {
    Layout l = new Layout();
    assertThat(l.getNumberOfItems(), equalTo(0));
    assertThat(l.getItems().size(), equalTo(0));

    Item item = new Item(ItemType.Triplet, new Cell(0, 0));
    for (int i = 0; i < Layout.MAX_ITEM_NUM; i++) {
      assertTrue(l.canAddMore());
      l = l.addItem(item);
      assertTrue(l.hasItem(item));
      assertThat(l.getNumberOfItems(), equalTo(i + 1));
    }

    assertFalse(l.canAddMore());
    try {
      l.addItem(item);
      fail();
    } catch (IllegalStateException e) {
    }

    assertThat(l, not(equalTo(Layout.createDefault())));
    List<Item> items = new ArrayList<>(l.getItems());
    for (Item i : items) {
      assertThat(i, not(sameInstance(item)));
      assertThat(i, equalTo(item));
      l = l.removeItem(item.createClone());
    }

    assertThat(l.getNumberOfItems(), equalTo(0));
    assertThat(l, equalTo(new Layout()));

    try {
      l.removeItem(item);
      fail();
    } catch (IllegalArgumentException e) {
    }
  }