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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def subscribe(self, obj, handler):
 """Subscribes to status updates of the requested object. DEPRECATED The handler will be invoked when the controller sends a notification regarding changed state. The user can then further query the object for the state itself."""

    if not isinstance(obj, LutronEntity):
      raise InvalidSubscription("Subscription target not a LutronEntity")
    _LOGGER.warning("DEPRECATED: Subscribing via Lutron.subscribe is obsolete. "
                    "Please use LutronEntity.subscribe")
    if obj not in self._legacy_subscribers:
      self._legacy_subscribers[obj] = handler
      obj.subscribe(self._dispatch_legacy_subscriber, None)