docs: protected void redirectUser(UserRedirectRequiredException e,
  			HttpServletRequest request, HttpServletResponse response)
  			throws IOException {
  
  		String redirectUri = e.getRedirectUri();
  		UriComponentsBuilder builder = UriComponentsBuilder
  				.fromHttpUrl(redirectUri);
  		Map<String, String> requestParams = e.getRequestParams();
  		for (Map.Entry<String, String> param : requestParams.entrySet()) {
  			builder.queryParam(param.getKey(), param.getValue());
  		}
  
  		if (e.getStateKey() != null) {
  			builder.queryParam("state", e.getStateKey());
  		}
  
  		this.redirectStrategy.sendRedirect(request, response, builder.build()
  				.encode().toUriString());
  	}