Imports *vpn_path* to qualifying VRF tables.

        Import RTs of VRF table is matched with RTs from *vpn4_path* and if we
        have any common RTs we import the path into VRF.

def import_single_vpn_path_to_all_vrfs(self, vpn_path, path_rts=None):
        """Imports *vpn_path* to qualifying VRF tables.

        Import RTs of VRF table is matched with RTs from *vpn4_path* and if we
        have any common RTs we import the path into VRF.
        """
        LOG.debug('Importing path %s to qualifying VRFs', vpn_path)

        # If this path has no RTs we are done.
        if not path_rts:
            LOG.info('Encountered a path with no RTs: %s', vpn_path)
            return

        # We match path RTs with all VRFs that are interested in them.
        interested_tables = set()

        # Get route family of VRF to when this VPN Path can be imported to
        if vpn_path.route_family == RF_IPv4_VPN:
            route_family = RF_IPv4_UC
        elif vpn_path.route_family == RF_IPv6_VPN:
            route_family = RF_IPv6_UC
        elif vpn_path.route_family == RF_L2_EVPN:
            route_family = RF_L2_EVPN
        elif vpn_path.route_family == RF_VPNv4_FLOWSPEC:
            route_family = RF_IPv4_FLOWSPEC
        elif vpn_path.route_family == RF_VPNv6_FLOWSPEC:
            route_family = RF_IPv6_FLOWSPEC
        elif vpn_path.route_family == RF_L2VPN_FLOWSPEC:
            route_family = RF_L2VPN_FLOWSPEC
        else:
            raise ValueError('Unsupported route family for VRF: %s' %
                             vpn_path.route_family)

        for rt in path_rts:
            rt_rf_id = rt + ':' + str(route_family)
            vrf_rt_tables = self._tables_for_rt.get(rt_rf_id)
            if vrf_rt_tables:
                interested_tables.update(vrf_rt_tables)

        if interested_tables:
            # We iterate over all VRF tables that are interested in the RT
            # of the given path and import this path into them.
            route_dist = vpn_path.nlri.route_dist
            for vrf_table in interested_tables:
                if (vpn_path.source is not None or
                        route_dist != vrf_table.vrf_conf.route_dist):
                    update_vrf_dest = vrf_table.import_vpn_path(vpn_path)
                    # Queue the destination for further processing.
                    if update_vrf_dest is not None:
                        self._signal_bus.\
                            dest_changed(update_vrf_dest)
        else:
            # If we do not have any VRF with import RT that match with path RT
            LOG.debug('No VRF table found that imports RTs: %s', path_rts)