code: 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());
      }
docs: Delete blacklist whose users belong to another app from a given user.
  @param username The owner of the blacklist
  @param blacklists CrossBlacklist array
  @return No content
  @throws APIConnectionException connect exception
  @throws APIRequestException request exception