Aerys\Root::fetchCachedStat PHP Method

    private function fetchCachedStat(string $reqPath, Request $request)
    {
        // We specifically allow users to bypass cached representations in debug mode by
        // using their browser's "force refresh" functionality. This lets us avoid the
        // annoyance of stale file representations being served for a few seconds after
        // changes have been written to disk.
        if (empty($this->debug)) {
            return $this->cache[$reqPath] ?? null;
        }
        foreach ($request->getHeaderArray("Cache-Control") as $value) {
            if (strcasecmp($value, "no-cache") === 0) {
                return null;
            }
        }
        foreach ($request->getHeaderArray("Pragma") as $value) {
            if (strcasecmp($value, "no-cache") === 0) {
                return null;
            }
        }
        return $this->cache[$reqPath] ?? null;
    }