private function isGoodHttpReferer(Sanitizer $sanitizer)
{
//Sanitize an extra scalar value inside of INPUT_SERVER.
$sanitizer->httpRefererExists();
$sanitizer->httpRefererHasGoodSize();
$sanitizer->setExtInputElement('HTTP_REFERER');
$sanitizer->sanitizeElement();
//Validate the extra scalar value from INPUT_SERVER.
$this->setFilteredExtElement($sanitizer->getFilteredExtElement());
return $this->validateFilteredElement();
}