class HomeController {
    @GetMapping("/")
    public String home(ModelMap modelMap, Authentication authentication) {<FILL_FUNCTION_BODY>}
}

        OAuth2Authentication oauth2Authentication = (OAuth2Authentication)authentication;
        modelMap.put("username", oauth2Authentication.getName());
        modelMap.put("authorities", oauth2Authentication.getAuthorities());
        modelMap.put("clientId", oauth2Authentication.getOAuth2Request().getClientId());
        OAuth2AuthenticationDetails details = (OAuth2AuthenticationDetails)oauth2Authentication.getDetails();
        modelMap.put("token", details.getTokenValue());
        return "index";
    
<no_super_class>