code: public void reset()
      {
          for (final Tile tile : revealed)
          {
              final Tile reset = new TileGame(tile.getSheet(),
                                              FOG,
                                              tile.getX(),
                                              tile.getY(),
                                              tile.getWidth(),
                                              tile.getHeight());
              map.setTile(reset);
          }
          revealed.clear();
      }
docs: Reset the revealed tiles to fogged.