Error filtering template: Notice: unserialize(): Error at offset magento widget

<?php

use MagentoFrameworkAppBootstrap;
use MagentoWidgetHelperConditions;
require __DIR__ . '/app/bootstrap.php';

$bootstrap = Bootstrap::create(BP, $_SERVER);

$obj = $bootstrap->getObjectManager();

$state = $obj->get('MagentoFrameworkAppState');
$state->setAreaCode('frontend');
$cons= array(
    "1"=>array(
        "type"=>'MagentoCatalogWidgetModelRuleConditionCombine',
        "aggregator"=>'all',
        "value"=>'1',
        "new_child"=>'',
    ),
    "1--1"=>array(
        'type'=>'MagentoCatalogWidgetModelRuleConditionProduct',
        'attribute'=>'sku',
        'operator'=>'()',
        'value'=>'crowe-sweater,Easy Full Dress,Herve Leger,Striped Maxi Dress,Daisy Lace Trim Blouse',
    )
);
$a=new Conditions();
$s=$a->encode($cons);
echo "<pre>";
echo($s);
echo "</pre>";exit;