anchor.diff:  handle_call(_, _From, State) ->
       {reply, invalid, State}.
   
  -% -----------------------------------------------------------------------------
  +% -------------------------------------------------------------------------
   
   handle_cast(_, State) ->
       {noreply, State}.
   
  -% -----------------------------------------------------------------------------
  +% -------------------------------------------------------------------------
   
   handle_info(_, State) ->
       {noreply, State}.
   
  -% -----------------------------------------------------------------------------
  +% -------------------------------------------------------------------------
   
   terminate(Reason, _State) ->
   	?info("Terminating due to ~p.", [Reason]),
  
positive.code: code_change(_OldVersion, State, _Extra) ->
  	{reply, State}.
  
  %% ----------------------------------------------------------------------------
  %% Internal API
  %% ----------------------------------------------------------------------------
  
  %% @doc Authenticate user against mongo
  handle_auth(Username, Password, State) ->
  
negative.code: %% ------------------------------------------------------------------------
  %% @doc Precursors Server MongoDB based authentication module.
  %%
  %% @copyright 2012 Christopher S. Case
  %% Licensed under the MIT license; see the LICENSE file for details.
  %% ------------------------------------------------------------------------
  -module(mongo_auth).
  %-behavior(pre_gen_auth).
  
  % -------------------------------------------------------------------------
  
  % gen_server
  -export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, 
  