DataSift\Storyplayer\PlayerLib\Story_Checkpoint::__isset PHP Метод

magic method to tell if the data is stored in the checkpoint or not

public __isset ( string $key ) : boolean
$key	string	the name of the data to test for
Результат	boolean	TRUE if the data exists in the checkpoint FALSE if the data does not exist in the checkpoint

    public function __isset($key)
    {
        return isset($this->data[$key]);
    }

Story_Checkpoint