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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 _enable_notifications_failed(self, dbus_error):
 """ Called when notification enabling has failed. """

        if ((dbus_error.get_dbus_name() == 'org.bluez.Error.Failed') and
            ((dbus_error.get_dbus_message() == "Already notifying") or
             (dbus_error.get_dbus_message() == "No notify session started"))):
            # Ignore cases where notifications where already enabled or already disabled
            return
        error = _error_from_dbus_error(dbus_error)
        self.service.device.characteristic_enable_notifications_failed(characteristic=self, error=error)