code: def update_local_rt_nlris(self):
          
          current_conf_import_rts = set()
          for vrf in self._vrfs_conf.vrf_confs:
              current_conf_import_rts.update(vrf.import_rts)
  
          removed_rts = self._all_vrfs_import_rts_set - current_conf_import_rts
          new_rts = current_conf_import_rts - self._all_vrfs_import_rts_set
          self._all_vrfs_import_rts_set = current_conf_import_rts
  
          # Add new and withdraw removed local RtNlris
          for new_rt in new_rts:
              self.add_rt_nlri(new_rt)
          for removed_rt in removed_rts:
              self.add_rt_nlri(removed_rt, is_withdraw=True)
docs: Does book-keeping of local RT NLRIs based on all configured VRFs.
  
          Syncs all import RTs and RT NLRIs.
          The method should be called when any VRFs are added/removed/changed.