anchor.diff:  health_fsm(waiting, suspend, _Service, InCheck) ->
       case InCheck#health_check.interval_tref of
           undefined -> ok;
  -        _ -> erlang:cancel_timer(InCheck#health_check.interval_tref),
  -             ok
  +        _ ->
  +            _ = erlang:cancel_timer(InCheck#health_check.interval_tref),
  +            ok
       end,
       {ok, suspend, InCheck#health_check{interval_tref = undefined}};
   
  
positive.code:         error ->
              Healths;
          {ok, Check} ->
              health_fsm(remove, ServiceId, Check),
              orddict:erase(ServiceId, Healths)
      end,
      State#state{health_checks = Healths2}.
  
negative.code: health_fsm(waiting, remove, _Service, InCheck) ->
      case InCheck#health_check.interval_tref of
          undefined -> ok;
          Tref ->
              _ = erlang:cancel_timer(Tref),
              ok
      end,
      OutCheck = InCheck#health_check{interval_tref = undefined},
      {remove, waiting, OutCheck};
  