code: def unsubscribe(self, coro):
          
          if coro in self._notify:
              self._notify.remove(coro)
              return True
          return False
docs: Unsubscribe from status updates from the Opentherm Gateway.
          Can only be used after connect()
          @coro is a coroutine which has been subscribed with subscribe()
          earlier.
          Return True on success, false if not connected or subscribed.