anchor.diff:  
   -include("mongo_protocol.hrl").
   
  --export([start_link/1, disconnect/1]).
  +-export([start_link/1, disconnect/1, hibernate/1]).
   -export([
     init/1,
     handle_call/3,
  
positive.code: %% @hidden
  handle_cast(halt, State) ->
    {stop, normal, State};
  handle_cast(_, State) ->
    {noreply, State}.
  
  
negative.code: try_register(Options) ->
    case lists:keyfind(register, 1, Options) of
      false -> ok;
      {_, Name} when is_atom(Name) -> register(Name, self());
      {_, RegFun} when is_function(RegFun) -> RegFun(self())
    end.