code: def atlas_peer_set_zonefile_status( peer_hostport, zonefile_hash, present, zonefile_bits=None, peer_table=None, con=None, path=None ):
      
      if zonefile_bits is None:
          zonefile_bits = atlasdb_get_zonefile_bits( zonefile_hash, con=con, path=path )
  
      with AtlasPeerTableLocked(peer_table) as ptbl:
          if ptbl.has_key(peer_hostport):
              peer_inv = atlas_peer_get_zonefile_inventory( peer_hostport, peer_table=ptbl )
              peer_inv = atlas_inventory_flip_zonefile_bits( peer_inv, zonefile_bits, present )
              atlas_peer_set_zonefile_inventory( peer_hostport, peer_inv, peer_table=ptbl )
                  
      return
docs: Mark a zonefile as being present or absent on a peer.
      Use this method to update our knowledge of what other peers have,
      based on when we try to ask them for zonefiles (i.e. a peer can
      lie about what zonefiles it has, and if it advertizes the availability
      of a zonefile but doesn't deliver, then we need to remember not
      to ask it again).