code: def path(self):
  		'''return relative path of tile image'''
  		(x, y) = self.tile
  		return os.path.join('%u' % self.zoom,
  				    '%u' % y,
  				    '%u.img' % xf path(self):
  		'''return relative path of tile image'''
  		(x, y) = self.tile
  		return os.path.join('%u' % self.zoom,
  				    '%u' % y,
  				    '%u.img' % x)
docs: return relative path of tile image