saveCacheFile example

        $key = $this->classNameHashes[$class->name];

        if (isset($this->loadedAnnotations[$key])) {
            return $this->loadedAnnotations[$key];
        }

        $path = $this->dir . '/' . strtr($key, '\\', '-') . '.cache.php';
        if (! is_file($path)) {
            $annot = $this->reader->getClassAnnotations($class);
            $this->saveCacheFile($path, $annot);

            return $this->loadedAnnotations[$key] = $annot;
        }

        $filename = $class->getFilename();
        if (
            $this->debug
            && $filename !== false
            && filemtime($path) < filemtime($filename)
        ) {
            @unlink($path);