anchor.diff:  
   handle_tracker_contact(S, Event) ->
       {ok, NextContactTime, NS} = contact_tracker(S, Event),
  +    io:format("installing timer at ~B ms~n", [NextContactTime * 1000]),
       TimerRef = gen_fsm:start_timer(NextContactTime * 1000, may_contact),
       NS#state{timer = TimerRef}.
   
  
positive.code: %% does not return until Module:init/1 has returned.
  %%--------------------------------------------------------------------
  start_link(ControlPid, StatePid, Url, InfoHash, PeerId) ->
      gen_fsm:start_link({local, ?SERVER}, ?MODULE,
  		       [{ControlPid, StatePid, Url, InfoHash, PeerId}],
  		       []).
  
  
negative.code: 		timer = none,
  	        control_pid = none}).
  
  -define(DEFAULT_REQUEST_TIMEOUT, 180).
  
  %%====================================================================
  