*
   * @throws IOException if a communications error occurs
   * @throws UnknownHostException if the Cyc server cannot be found
   * @throws CycApiException if the Cyc server returns an error
   */
  public CycConstant getKnownConstantByName(String constantName)
          throws UnknownHostException, IOException, CycApiException {
    CycConstant cycConstant = getConstantByName(constantName);

    if (cycConstant == null) {
      throw new CycApiException("Expected constant not found " + constantName);
    }

    return cycConstant;
  }