code: protected void handle(Authentication authentication) throws IOException, ServletException {
          HttpServletRequest request = http.getCurrentRequest();
          HttpServletResponse response = http.getCurrentResponse();
          String targetUrl = determineTargetUrl(request, response);
  
          if (response.isCommitted()) {
              logger.debug("Response has already been committed. Unable to redirect to " + targetUrl);
              return;
          } else {
              logger.debug("Redirecting to " + targetUrl);
          }
  
          redirectStrategy.sendRedirect(targetUrl);
      }
docs: Invokes the configured {@code RedirectStrategy} with the URL returned by the {@code determineTargetUrl} method.
  <p/>
  The redirect will not be performed if the response has already been committed.