def METHOD_NAME(self, level):
    """Get tile info for a particular level.
    Override the tiles.py method.
    level  the level to get tile info for
    Returns (num_tiles_x, num_tiles_y, ppd_x, ppd_y) or None if 'levels'
    doesn't exist.
    """
    # is required level available?
    if level not in self.levels:
        return None
    # see if we can open the tile info file.
    info_file = os.path.join(self.tiles_dir, '%d' % level, TileInfoFilename)
    try:
        with open(info_file, 'rb') as fd:
            info = pickle.load(fd)
    except IOError:
        info = None
    return info