Adds HTTP headers to specify that the Response needs to be parsed for ESI.
This method only adds an ESI HTTP header if the Response has some ESI tags.
Response $response A Response instance:
public function addSurrogateControl(Response $response) {
if (false !== strpos($response
->getContent(), '<esi:include')) {
$response->headers
->set('Surrogate-Control', 'content="ESI/1.0"');
}
}