public function create($cacheFilePath = null)
    {
        $map = [];
        if ($cacheFilePath) {
            $map = $this->resolveCachedMap($cacheFilePath);
        }
        if (!is_array($map)) {
            $map = $this->createMap();
            if ($cacheFilePath) {
                $this->cacheMap($cacheFilePath, $map);
            }
        }

        $this->map = $map;

        return $map;
    }