docs: public ResponseWrapper deleteCrossBlacklist(String username, CrossBlacklist[] blacklists)
              throws APIConnectionException, APIRequestException {
          StringUtils.checkUsername(username);
          CrossBlacklistPayload payload = new CrossBlacklistPayload.Builder()
                  .setCrossBlacklists(blacklists)
                  .build();
          return _httpClient.sendDelete(_baseUrl + crossUserPath + "/" + username + "/blacklist", payload.toString());
      }