title: Create new json element and push element in json in Shopify liquid files
body: <pre><code>{% cartitems = [{ 
  &quot;id&quot;:1,&quot;properties&quot;:{&quot;_bundle_sku&quot;:&quot;111&quot;&quot;},&quot;quantity&quot;:1},
  { &quot;id&quot;:2,&quot;properties&quot;:{&quot;_bundle_sku&quot;:&quot;222&quot;&quot;},&quot;quantity&quot;:1},
  { &quot;id&quot;:3,&quot;properties&quot;:{&quot;_bundle_sku&quot;:&quot;333&quot;&quot;},&quot;quantity&quot;:1},
  { &quot;id&quot;:4,&quot;properties&quot;:{&quot;_bundle_sku&quot;:&quot;222&quot;&quot;},&quot;quantity&quot;:1}
  }] %}
  </code></pre>
  <p>This is for example I am getting result of my cart items and now I like to keep items together whose _bundle_sku values are same. But I don't find any help to manipulate cart json object in shopify liquid files.</p>
  <p>So here I like the response to achieve like following -</p>
  <pre><code>{% cartitems = [{ 
  &quot;id&quot;:1,&quot;properties&quot;:{&quot;_bundle_sku&quot;:&quot;111&quot;&quot;},&quot;quantity&quot;:1},
  { &quot;id&quot;:2,&quot;properties&quot;:{&quot;_bundle_sku&quot;:&quot;222&quot;&quot;},&quot;quantity&quot;:1},
  { &quot;id&quot;:4,&quot;properties&quot;:{&quot;_bundle_sku&quot;:&quot;222&quot;&quot;},&quot;quantity&quot;:1},
  { &quot;id&quot;:3,&quot;properties&quot;:{&quot;_bundle_sku&quot;:&quot;333&quot;&quot;},&quot;quantity&quot;:1}
  }] %}
  </code></pre>
  <p>Please assist me how can I achieve this.
  many thanks.</p>