anchor.diff:  -export([start/1
            , start/2
            , stop/1
  +         , shutdown/1
            , print_state/1
            , get_state/1
            , get_state/2
  
positive.code:   gen_server:start_link({local, Mod}, ?MODULE, {Mod,Args}, []).
  
  stop(Mod) -> 
    try gen_server:cast(Mod,stop) 
    catch exit:{noproc,_} -> ok
    end.
  
  get_state(Mod,Field) ->
    case proplists:is_defined(Field,State = get_state(Mod)) of
  
negative.code:   end;
  expand_recs(_,Term) ->
    Term.
  
  cast(Mod,What) ->
    try gen_server:cast(Mod,What) 
    catch exit:{noproc,_} -> ok
    end.
  