code: def find_zonefile_origins( self, missing_zfinfo, peer_hostports ):
          
          zonefile_origins = {}   # map peer hostport to list of zonefile hashes
  
          # which peers can serve each zonefile?
          for zfhash in missing_zfinfo.keys():
              for peer_hostport in peer_hostports:
                  if not zonefile_origins.has_key(peer_hostport):
                      zonefile_origins[peer_hostport] = []
  
                  if peer_hostport in missing_zfinfo[zfhash]['peers']:
                      zonefile_origins[peer_hostport].append( zfhash )
  
          return zonefile_origins
docs: Find out which peers can serve which zonefiles