anchor.diff:  -define(LE_POLL_INTERVAL, timer:seconds(3)).
   % Number of polls about authorization status
   -define(LE_POLL_ATTEMPTS, 10).
  +
  +% Number of polls to DNS
  +-define(WAIT_FOR_TXT_ATTEMPTS, 70).
  +% Delay between polls to DNS. Total polling time should be longer than soa_minimum
  +% in onezone
  +-define(WAIT_FOR_TXT_DELAY, timer:seconds(2)).
  +
   % Number of failed request retries
   -define(GET_RETRIES, 3).
   -define(POST_RETRIES, 4).
  
positive.code:     AuthString = make_auth_string(Token, State),
      TxtValue = base64url:encode(crypto:hash(sha256, AuthString)),
  
      % requires oz connection
      ok = Service:set_txt_record(#{txt_name => ?LETSENCRYPT_TXT_NAME,
          txt_value => TxtValue, txt_ttl => ?LETSENCRYPT_TXT_TTL}),
  
      Payload = #{<<"resource">> => <<"challenge">>,
          <<"type">> => <<"dns-01">>,
          <<"keyAuthorization">> => AuthString},
      {ok, _, _, State2} = http_post(URI, Payload, 202, State),
      {ok, State2#flow_state{authz_uri = URI}}.
  
  
  %%--------------------------------------------------------------------
  
negative.code:             ?info("No staging ACME server URL defined. Skipping staging run and running in production mode."),
              production;
          {full, _} ->
              ?info("Let's Encrypt: Starting test run against staging server before actual "
              "Let's Encrypt certification"),
              full;
          {_, undefined} -> throw("No staging ACME server URL defined. Cannot perform test run"),
              throw({error, no_letsencrypt_staging_server});
  