code: public ResponseWrapper addBlackList(String username, String...users)
              throws APIConnectionException, APIRequestException {
          return _userClient.addBlackList(username, users);
      }
docs: Add Users to black list
  @param username The owner of the black list
  @param users The users that will add to black list
  @return add users to black list
  @throws APIConnectionException connect exception
  @throws APIRequestException request exception