code: public WebAuthenticator getSSOAuthenticator(WebRequest webRequest, String ssoCookieName) {
          SecurityMetadata securityMetadata = webRequest.getSecurityMetadata();
          SecurityService securityService = securityServiceRef.getService();
          SSOCookieHelper cookieHelper;
          if (ssoCookieName != null) {
              cookieHelper = new SSOCookieHelperImpl(webAppSecurityConfig, ssoCookieName);
          } else {
              cookieHelper = webAppSecurityConfig.createSSOCookieHelper();
          }
          return new SSOAuthenticator(securityService.getAuthenticationService(), securityMetadata, webAppSecurityConfig, cookieHelper);
      }
docs: Create an instance of SSOAuthenticator.
  
  @param webRequest
  @return The SSOAuthenticator, or {@code null} if it could not be created.