Computes current global interested RTs for global tables.

        Computes interested RTs based on current RT filters for peers. This
        filter should be used to check if for RTs on a path that is installed
        in any global table (expect RT Table).

def _compute_global_interested_rts(self):
        """Computes current global interested RTs for global tables.

        Computes interested RTs based on current RT filters for peers. This
        filter should be used to check if for RTs on a path that is installed
        in any global table (expect RT Table).
        """
        interested_rts = set()
        for rtfilter in self._peer_to_rtfilter_map.values():
            interested_rts.update(rtfilter)

        interested_rts.update(self._vrfs_conf.vrf_interested_rts)
        # Remove default RT as it is not a valid RT for paths
        # TODO(PH): Check if we have better alternative than add and remove
        interested_rts.add(RouteTargetMembershipNLRI.DEFAULT_RT)
        interested_rts.remove(RouteTargetMembershipNLRI.DEFAULT_RT)
        return interested_rts