public function retrieve(string $key)
  {
    $file = $this->file;

    if (file_exists($file)) {
      $data = unserialize($this->decrypt(file_get_contents($file)));

      if (isset($data[$key])) {
        return $data[$key];
      }
    }

    return null;
  }
public function retrieve(string $key)
  {
    $file = $this->file;

    if (file_exists($file)) {
      $data = unserialize($this->decrypt(file_get_contents($file)));

      if (isset($data[$key])) {
        return $data[$key];
      }
    }

    return null;
  }
public function retrieve ( string $ key ) { $ file = $ this -> file ; if ( file_exists ( $ file ) ) { $ data = unserialize ( $ this -> decrypt ( file_get_contents ( $ file ) ) ) ; if ( isset ( $ data [ $ key ] ) ) { return $ data [ $ key ] ; } } return null ; }
Retrieve cached value

@param string $key
@return mixed
Retrieve cached value