docs: public void onSiteOrProjectChange(String sitePath, String serverLink) {
  
          if (m_frame != null) {
              m_frame.removeFromParent();
              m_frame = null;
          }
          if (m_handler != null) {
              m_handler.onSiteOrProjectChange(sitePath, serverLink);
          } else {
              Window.Location.assign(serverLink);
          }
      }