anchor.diff:  
   -include("autocluster.hrl").
   
  --define(CREATE_SESSION_RETRY, 10).
  +-define(CREATE_SESSION_RETRIES, 10).
   
   
   %%--------------------------------------------------------------------
  
positive.code: 
  
  %% @doc Tries to create a session.
  %% if there is an Error 500 retries until ?CREATE_SESSION_RETRY
  
  -spec maybe_create_session(string(), pos_integer()) -> {ok,string()} | {error, string()}.
  maybe_create_session(Who, N) when N > 0 ->
  
negative.code: %% @end.
  -spec lock(string()) -> ok | {error, string()}.
  lock(Who) ->
      case maybe_create_session(Who, ?CREATE_SESSION_RETRIES) of
          {ok, SessionId} ->
              start_session_ttl_updater(SessionId),
              Now = time_compat:erlang_system_time(seconds),
  