anchor.diff:  update_feed_recency(LocalName) when is_binary(LocalName) ->
       Now = erlang:system_time(seconds),
       T = fun() -> [Feed] = mnesia:read(podrec_feed, LocalName),
  -                 mnesia:write(Feed#podrec_feed{last_fetch=Now})
  +                 mnesia:write(podrec_feed, Feed#file{last_fetch=Now}, write)
           end,
       {atomic, ok} = mnesia:transaction(T),
       ok.
  
positive.code: is_cached_file_recent(LocalName) when is_binary(LocalName) ->
      T = fun() -> mnesia:read(podrec_feed, LocalName) end,
      case mnesia:transaction(T) of
          {atomic, [#podrec_feed{last_fetch=LastFetch}]} ->
              % TODO: LastFetch might be undefined
              FeedRecent = podrec_util:get_env(feed_recent, 600),
              erlang:system_time(seconds) - LastFetch < FeedRecent;
          {atomic, []} ->
              false
      end.
  
negative.code: 
  -record(state, {jobs=#{}}).
  
  -record(file, {local_name, orig_url, last_fetch}).
  
  -compile(export_all).
  
  