code: public function read($id)
      {
          $path = $this->getPath($id);
  
          if (! file_exists($path)) {
              return '';
          }
  
          if (filemtime($path) < time() - $this->lifeTime) {
              return '';
          }
  
          return file_get_contents($path);
      }
docs: Read session data
  
  @param string $id
  
  @return string