'Add tap interface and handle interface missing exceptions.'

def add_tap_interface(self, network_id, network_type, physical_network, segmentation_id, tap_device_name, device_owner, mtu):

    try:
        return self._add_tap_interface(network_id, network_type, physical_network, segmentation_id, tap_device_name, device_owner, mtu)
    except Exception:
        with excutils.save_and_reraise_exception() as ctx:
            if (not ip_lib.device_exists(tap_device_name)):
                ctx.reraise = False
                return False
