code: public void changeProperty(String propertyName, Object propertyValue)
              throws ShanksException {
          this.properties.put(propertyName, propertyValue);
          this.checkStatus();
      }
docs: If the property exists, this method changes it. If not, this method
  creates it.
  
  @param propertyName
  @param propertyValue
  @throws UnsupportedNetworkElementFieldException