anchor.diff:  
   %% API
   -export([start_link/0,
  -         nodes_wanted/0,
  +         nodes_wanted/0, nodes_wanted/1,
            nodes_wanted_updated/0,
            nodes_actual/0,
            random_node/0,
  
positive.code:     {noreply, State}.
  
  % -----------------------------------------------------------
  
  % Read from ns_config nodes_wanted.
  
  do_nodes_wanted() ->
      case ns_config:search(nodes_wanted) of
          {value, L} -> lists:usort(L);
          false      -> []
      end.
  
  %% The core of what happens when nodelists change
  %% only used by do_nodes_wanted_updated
  
negative.code: 
  nodes_actual_proper() ->
      Curr = nodes_actual(),
      Want = nodes_wanted(),
      Diff = lists:subtract(Curr, Want),
      lists:usort(lists:subtract(Curr, Diff)).
  
  