anchor.diff:  -include_lib("../sip_common.hrl").
   -include_lib("sip.hrl").
   
  --record(state, {sending = [], callback, cstate}).
  +-record(state, {sending = [], mod, mod_state}).
   
   %% @doc Creates UA process as part of the supervision tree
   %%
  
positive.code: %%-----------------------------------------------------------------
  %% @private
  -spec init({module(), term()}) -> {ok, #state{}}.
  init({Callback, Args}) ->
      {ok, CState} = Callback:init(Args),
      State = #state{callback = Callback, cstate = CState},
      {ok, State}.
  
  %% @private
  -spec handle_call(term(), term(), #state{}) -> any().
  handle_call(Req, From, State) ->
      Callback = State#state.callback,
      Response = Callback:handle_call(Req, From, State#state.cstate),
      handle_response(Response, State).
  
  %% @private
  
negative.code: handle_cast({send, Id, Destinations, Request}, State) ->
      State2 = send_internal(Id, Destinations, Request, State),
      {noreply, State2};
  handle_cast(Req, #state{mod = Mod, mod_state = ModState} = State) ->
      Response = Mod:handle_cast(Req, ModState),
      handle_response(Response, State).
  
  %% @private
  