code: public void setExtProperty(String propName, String propValue) {
          if (m_extProperties == null) {
              m_extProperties = new HashMap<String, String>();
          }
          m_extProperties.put(propName, propValue);
  
      }
docs: Sets an extended property on the object.
  
  @param propName
  The extended property name, either a string, or URI as string.