anchor.diff:  		my_contact,		%% string(), the Contact: header value we use
   
   		notify_pids = [],	%% list() of pid(), active NOTIFY client transactions
  -		subscription_state,	%% active | pending | terminated
  +		subscription_state,	%% active | pending | deactivated | terminated
   		last_notify_content,	%% undefined | {Body, ExtraHeaders} - parameters of the last NOTIFY we sent
   		subscr_num,		%% integer(), number of SUBSCRIBEs we have accepted
   		notification_rate,	%% integer(), milliseconds required between NOTIFYs for the current event package
  
positive.code: 	    %% supposed to send as a result of the initial SUBSCRIBE? Subsequent SUBSCRIBE?
  	    State;
  	{ok, Body, ExtraHeaders, NewPkgState} when is_list(Body); is_binary(Body), is_list(ExtraHeaders) ->
  	    case ({Body, ExtraHeaders} == State#state.last_notify_content) of
  		true ->
  		    logger:log(debug, "Subscription: Supressed sending of NOTIFY identical (essentially) "
  			       "to the last one we sent."),
  		    State;
  		false ->
  		    NewState1 = send_notify_request(State, Body, ExtraHeaders),
  		    NewState1#state{last_notify_content = {Body, ExtraHeaders},
  				    event_pkg_state     = NewPkgState
  				   }
  	    end
  
negative.code: 	false ->
  	    process_timer_signal(send_notify, undefined, State)
      end;
  
  %%--------------------------------------------------------------------
  %% Function: handle_cast({terminate, Mode}, State)
  %%           Mode = atom(), shutdown | graceful | ...
  %% Descrip.: Terminate the subscription since the eventserver is
  %%           shutting down.
  %% Returns :    {stop, Reason, State}
  %%--------------------------------------------------------------------
  handle_cast({terminate, Mode}, State) when is_atom(Mode) ->
      NewState =
  	case State#state.subscription_state of
  	    S when S == active; S == pending ->
  		logger:log(debug, "Subscription: Deactivating subscription"),
  		prepare_and_send_notify(State#state{subscription_state = deactivated});
  	    _ ->
  		State
  	end,
      {stop, normal, NewState};
  
  handle_cast(Msg, State) ->
      logger:log(error, "Subscription: Received unknown gen_server cast : ~p", [Msg]),
  