code: protected FormLoginAuthenticator createFormLoginAuthenticator(WebRequest webRequest) {
          WebAuthenticator ssoAuthenticator = providerAuthenticatorProxy.getSSOAuthenticator(webRequest, null);
          return new FormLoginAuthenticator(ssoAuthenticator, webAppSecurityConfig, providerAuthenticatorProxy);
      }
docs: Create an instance of the FormLoginAuthenticator.
  <p>
  Protected so it can be overridden in unit tests.