void crush(CellPool pool, Cell[][] cellMatrix) {
    //take out from this position and put back in pool
    pool.addNewCell(this);
    this.fillThisSpace(pool, cellMatrix);
  }
@Test
  void crushTest() {
    var c1 = new Candy("green jelly", "jelly", Type.CRUSHABLE_CANDY, 5);
    var c2 = new Candy("purple candy", "candy", Type.CRUSHABLE_CANDY, 5);
    var matrix = new Cell[4][4];
    matrix[0][0] = new Cell(c1, 0, 0);
    matrix[1][0] = new Cell(c2, 0, 1);
    matrix[1][0].crush(new CellPool(5), matrix);
    assertEquals("green jelly", matrix[1][0].candy.name);
  }