bool mustRevalidate() Returns true if the response must be revalidated by caches. This

string getRequestFormat(string $default = 'html') Gets the request format. Here is the

SessionInterface|null

addCacheControlDirective(string $key, mixed $value = true) Adds a custom Cache-Control directive

bool contains(string $key, string $value) Returns true if the given HTTP header contains the

static array getTrustedProxies() Gets the list of trusted proxies.

RedirectResponse setTargetUrl(string

bool isEmpty() Is the response empty?

class ParameterBag implements IteratorAggregate,

string|null getEtag() Returns the literal value of the ETag HTTP header.