anchor.diff:  
   select_auth_infos(KeySpec) ->
       replicated_dets:select(storage_name(), {auth, KeySpec}, 100).
  -
  --spec get_identity({rbac_identity(), []}) -> rbac_identity().
  -get_identity({Identity, _}) ->
  -    Identity.
   
   build_auth(false, undefined, _UserName) ->
       password_required;
  
positive.code:     [{{Username, builtin}, get_salt_and_mac(get_auth_info(Props))} ||
          {{Username, builtin}, Props} <- Users].
  
  -spec get_memcached_auth_infos([{rbac_identity(), []}]) -> list().
  get_memcached_auth_infos(Users) ->
      [get_memcached_auth(get_auth_info(Props)) ||
          {{_Username, builtin}, Props} <- Users].
  
  -spec get_user_roles({rbac_identity(), []}) -> [rbac_role()].
  get_user_roles({_Identity, Props}) ->
      proplists:get_value(roles, Props, []).
  
  -spec get_roles(rbac_identity()) -> [rbac_role()].
  get_roles(Identity) ->
      Props =
  
negative.code: 
  -export([get_users/1,
           select_users/1,
           select_auth_infos/1,
           store_user/4,
           delete_user/1,
  