code: public ResponseWrapper addCrossBlacklist(String username, CrossBlacklist[] blacklists)
              throws APIConnectionException, APIRequestException {
          return _crossAppClient.addCrossBlacklist(username, blacklists);
      }
docs: Add blacklist whose users belong to another app to 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