code: private VerticalLayout createEnableGoogleAuthButton() {
  		final VerticalLayout formLayout = new VerticalLayout();
  		formLayout.setSizeFull();
  
  		final Panel formPanel = new Panel();
  		formPanel.setSizeFull();
  
  		formLayout.addComponent(formPanel);
  
  		final FormLayout formContent = new FormLayout();
  		formPanel.setContent(formContent);
  
  		final SetGoogleAuthenticatorCredentialRequest request = new SetGoogleAuthenticatorCredentialRequest();
  		request.setSessionId(RequestContextHolder.currentRequestAttributes().getSessionId());
  		request.setUserpassword("");
  		final ClickListener listener = new SetGoogleAuthenticatorCredentialClickListener(request);
  		getFormFactory().addRequestInputFormFields(formContent, request, SetGoogleAuthenticatorCredentialRequest.class,
  				AS_LIST, ENABLE_GOOGLE_AUTHENTICATOR, listener);
  
  		return formLayout;
  	}
docs: Creates the enable google auth button.
  
  @return the vertical layout