Security/LdapGuardAuthenticator.php
public function start(Request $request, AuthenticationException $authException = null)
    {
        $entryPoint = $this->options['http_basic'] ? new BasicAuthenticationEntryPoint($this->getHttpBasicRealm()) : $this->entryPoint;
        $event = new AuthenticationHandlerEvent(
            $entryPoint->start($request, $authException),
            $request,
            $authException
        );
        $this->dispatcher->dispatch(AuthenticationHandlerEvent::START, $event);

        return $event->getResponse();
    }
public function start(Request $request, AuthenticationException $authException = null)
    {
        $entryPoint = $this->options['http_basic'] ? new BasicAuthenticationEntryPoint($this->getHttpBasicRealm()) : $this->entryPoint;
        $event = new AuthenticationHandlerEvent(
            $entryPoint->start($request, $authException),
            $request,
            $authException
        );
        $this->dispatcher->dispatch(AuthenticationHandlerEvent::START, $event);

        return $event->getResponse();
    }
{@inheritdoc}