Uses the _get_aggregated_node_list structure to find
        the primary mac address associated to a secondary one,
        if none is found returns itself.

def _get_primary_address(self, mac_address, node_list):
        """
        Uses the _get_aggregated_node_list structure to find
        the primary mac address associated to a secondary one,
        if none is found returns itself.
        """
        for local_addresses in node_list:
            if mac_address in local_addresses:
                return local_addresses[0]
        return mac_address