for (int i = 0; i < data.length; i++) { data[i] = 0; }
   public void validate()   {      lastused = System.currentTimeMillis();      if (location == LOCATION_MEMORY)      {         return;      }      else if (location == LOCATION_DISK)      {         loadTile();         return;      }      else // location == LOCATION_INVALID         {         data = new int[TILE_SIZE * TILE_SIZE];         for (int i = 0; i < data.length; i++)         {            data[i] = 0;         }         location = LOCATION_MEMORY;      }   }