anchor.diff:           get_v1_time/1,
            get_v3/1,
            get_v4/0,
  -         get_v4_fast/0,
  -         get_v4_safe/0,
            get_v5/1,
            uuid_to_string/1,
            increment/1]).
  
positive.code: % if OpenSSL was compiled in FIPS mode, it uses ANSI X9.31 RNG
  % and would have collisions based on 3DES (which is a black-box algorithm,
  % i.e., the DES S-boxes used within the cipher were never published).
  get_v4_safe() ->
      <<Rand1:60, _:4, Rand2:6, _:2, Rand3:56>> = crypto:rand_bytes(16),
      <<Rand1:60,
        0:1, 1:1, 0:1, 0:1,  % version 4 bits
  
negative.code:       0:1, 1:1,            % reserved bits
        B3:56>>.
  
  % crypto:rand_bytes/1 repeats in the same way as
  % RAND_pseudo_bytes within OpenSSL.
  % if OpenSSL is configured to use the MD PRNG (default) with SHA1
  