public function toJson()
    {
        $json = array();
        $json['id'] = $this->id;
        $json['from'] = $this->from;
        $json['color'] = $this->color;
        $json['message'] = $this->message;
        $json['notify'] = $this->notify;
        $json['message_format'] = $this->messageFormat;
        $json['date'] = $this->date;

        return $json;

    }