DataSift\Storyplayer\PlayerLib\Story_Checkpoint::__set PHP Method

    public function __set($key, $value)
    {
        // what are we doing?
        $log = usingLog()->startAction("store '{$key}' in the checkpoint");
        // are we allowed to change the data at this time?
        if ($this->readOnly) {
            // no, we are not
            $log->endAction("checkpoint is readonly; did not store '{$key}'");
            throw new E5xx_CheckpointIsReadOnly();
        }
        // if we get here, we're allowed to change the checkpoint
        $this->data[$key] = $value;
        // all done
        $log->endAction($value);
    }