'When a circuit breaks and it affects our operation we should re-add the
peers when a new circuit is available
@param Circuit broken_circuit: the circuit that has been broken
@return Set with destinations using this circuit'

def circuit_dead(self, broken_circuit):

    affected_destinations = set((destination for (destination, tunnel_circuit) in self.destinations.iteritems() if (tunnel_circuit == broken_circuit)))
    counter = 0
    for destination in affected_destinations:
        if (destination in self.destinations):
            del self.destinations[destination]
            counter += 1
    if (counter > 0):
        self._logger.debug('Deleted    %d    peers    from    destination    list', counter)
    return affected_destinations
