anchor.diff:  
   -behaviour(gen_server).
   
  +-include("timeouts.hrl").
  +-include("proto/oneclient/message_id.hrl").
  +-include("proto/oneclient/client_messages.hrl").
  +-include("proto/oneclient/server_messages.hrl").
  +
   %% API
  +-export([start_link/0]).
   -export([
  -    start_link/0,
  -    communicate/0,
  -    send_sync/0, send_async/0,
  +    communicate/2,
  +    send_sync/2, send_sync/3,
  +    send_async/2,
       respond/0
   ]).
   
  
positive.code: code_change(_OldVsn, State, _Extra) ->
      {ok, State}.
  
  %%%===================================================================
  %%% Internal functions
  %%%===================================================================
  
negative.code: %% @end
  %%--------------------------------------------------------------------
  -spec handle_cast(Request :: term(), state()) ->
      {noreply, NewState :: state()} |
      {noreply, NewState :: state(), timeout() | hibernate} |
      {stop, Reason :: term(), NewState :: state()}.
  handle_cast(_Request, State) ->
      {noreply, State}.
  
  
  %%--------------------------------------------------------------------
  %% @private
  %% @doc
  