@Test
  public void testNegativePoints() {
    // first player's move
    scrabbleSystem.isValid(moveList1, specialMoveList1);
    scrabbleSystem.move(moveList1, specialMoveList1);
    // second player's move, it will trigger special tile
    scrabbleSystem.nextPlayer();
    scrabbleSystem.getCurrentPlayer().setPlayerPoints(50);
    scrabbleSystem.isValid(moveList2, specialMoveList2);
    scrabbleSystem.move(moveList2, specialMoveList2);

    /*
     * the points should be (50 - 9) = 41, since the word points are set to
     * negative
     */
    assertEquals(41, scrabbleSystem.getCurrentPlayer().getPlayerPoints());
  }