anchor.diff:  -export_type([timestamp/0]).
   
   -type ext_binary() :: binary().
  +-type map() :: term(). %% FIXME: remove when handled internally.
   -type timestamp() :: {MegaSecs :: non_neg_integer(),
                         Secs :: non_neg_integer(),
                         MicroSecs :: non_neg_integer()}.
  
positive.code: -export([list_to_bitstring/1, list_to_existing_atom/1, list_to_float/1]).
  -export([list_to_integer/1, list_to_integer/2]).
  -export([list_to_pid/1, list_to_tuple/1, loaded/0]).
  -export([localtime/0, make_ref/0, match_spec_test/3, md5/1, md5_final/1]).
  -export([md5_init/0, md5_update/2, module_loaded/1, monitor/2]).
  -export([monitor_node/2, monitor_node/3, nif_error/1, nif_error/2
  ]).
  -export([node/0, node/1, now/0, phash/2, phash2/1, phash2/2]).
  -export([pid_to_list/1, port_close/1, port_command/2, port_command/3]).
  -export([port_connect/2, port_control/3, port_get_data/1]).
  
negative.code: make_ref() ->
      erlang:nif_error(undefined).
  
  %% Shadowed by erl_bif_types: erlang:map_size/1
  -spec map_size(Map) -> non_neg_integer() when
        Map :: map().
  map_size(_Map) ->
      erlang:nif_error(undefined).
  
  %% match_spec_test/3
  -spec erlang:match_spec_test(P1, P2, P3) -> TestResult when
        P1 :: [term()] | tuple(),
  