docs: private String buildClientVariantUrl(String context, CmsClientVariantInfo info) {
  
          String currentUrl = Window.Location.getHref();
          // remove fragment
          currentUrl = currentUrl.replaceFirst("#.*$", "");
          String connector = "?";
          if (currentUrl.indexOf('?') >= 0) {
              connector = "&";
          }
          String targetUrl = currentUrl + connector + CmsGwtConstants.PARAM_TEMPLATE_CONTEXT + "=" + context;
          return targetUrl;
      }