def __init__ (self, link, scheduler, table, pos, angle, into = None,
         level = 0, exclude = exclude):
     Observable.__init__ (self)
     DistanceSensor.__init__ (self, table, pos, angle, self.RANGE, into,
             level, exclude)
     self.link = link
     self.scheduler = scheduler
     self.value = None
     self.register (self.__update)
     self.evaluate ()
 def __init__ (self, *args):
     Observable.__init__ (self)
     DistanceSensor.__init__ (self, *args)