Unregister the given switch address.

    Unregisters the given switch address to let
    ryu.controller.controller.OpenFlowController stop trying to initiate
    connection to switch.

    :param addr: A tuple of (host, port) pair of switch.

def unregister_switch_address(addr):
    """
    Unregister the given switch address.

    Unregisters the given switch address to let
    ryu.controller.controller.OpenFlowController stop trying to initiate
    connection to switch.

    :param addr: A tuple of (host, port) pair of switch.
    """
    ofp_handler = app_manager.lookup_service_brick(ofp_event.NAME)
    # Do nothing if ofp_handler is not started yet
    if ofp_handler.controller is None:
        return
    ofp_handler.controller.stop_client_loop(addr)