(PECL pecl_http >= 0.10.0)
HttpResponse::setCacheControl — Set cache control
Define a custom Cache-Control header, usually being private or public;
the primary cache control setting
the max-age in seconds, suggesting how long the cache entry is valid on the client side
whether the cached entity should be revalidated by the client for every request
Returns TRUE on success, or FALSE if control does not match one of public, private or no-cache.