code: public function minify($content, $options)
      {
          if ($this->cacheDir) {
              if (!file_exists($this->cacheDir)) {
                  mkdir($this->cacheDir, 0777, true);
              }
  
              $hash = md5($content);
              $file = implode(DIRECTORY_SEPARATOR, array($this->cacheDir, $hash));
              if (!file_exists($file)) {
                  file_put_contents($file, \JShrink\Minifier::minify($content, $options));
              }
  
              return file_get_contents($file);
          } else {
              return \JShrink\Minifier::minify($content, $options);
          }
      }
docs: {@inheritdoc}