anchor.diff:  start_link() ->
       gen_server:start_link({local, ?SERVER}, ?MODULE, {}, []).
   
  +create_session(DialogId) ->
  +    ok.
  +
  +terminate_session(DialogId) ->
  +    ok.
   
   -spec create_dialog(uac | uas, #sip_request{}, #sip_response{}) -> ok.
   %% @doc Create new dialog for given pair of request/response
  
positive.code:         true ->
              Owner = ets:lookup_element(State#state.table, DialogId, #sip_dialog.owner),
              true = ets:delete(State#state.table, DialogId),
              % notify
              gen_event:notify(sip_dialog_man, {dialog_terminated, DialogId, Owner}),
              {reply, ok, State};
  
negative.code: 
  %% API
  -export([start_link/0, create_dialog/3, terminate_dialog/1, lookup_dialog/1, next_local_seq/1, update_remote_seq/2, list_dialogs/0, dialog_id/2]).
  -export([create_session/1, terminate_session/1]).
  
  %% Server callbacks
  -export([init/1, terminate/2, code_change/3]).
  