code: def atlas_peer_get_zonefile_inventory( peer_hostport, peer_table=None ):
      
      inv = None
  
      with AtlasPeerTableLocked(peer_table) as ptbl:
          if peer_hostport not in ptbl.keys():
              return None
  
          inv = ptbl[peer_hostport]['zonefile_inv']
  
      return inv
docs: What's the zonefile inventory vector for this peer?
      Return None if not defined