code: public boolean parseUnrecognizedElement(Element element, Properties props) throws Exception {
          if ("connectionSource".equals(element.getNodeName())) {
              Object instance =
                      DOMConfigurator.parseElement(element, props, ConnectionSource.class);
              if (instance instanceof ConnectionSource) {
                 ConnectionSource source = (ConnectionSource) instance;
                 source.activateOptions();
                 setConnectionSource(source);
              }
              return true;
          }
          return false;
    }
docs: {@inheritDoc}