title: How to select element from HTMLElement
body: <p>I am trying to select elements from the HTML Element. But not working. How to do it? I have used query selector but it is not working. Only it is working inside settimeout. Without settimeout how to achieve?</p>
  <p><strong>HTML:</strong> Getting this from <code>console.log(drop);</code></p>
  <pre><code>&lt;div class=&quot;container&quot;&gt;
  &lt;dropdown-part&gt;
   &lt;select&gt;
   &lt;option&gt;2&lt;/option&gt;
   &lt;/select&gt;
  &lt;/dropdown-part&gt;
  &lt;/div&gt;
  </code></pre>
  <p><strong>TypeScript:</strong></p>
  <pre><code>let dropcover = this.shadowRoot.querySelector('.container') as HTMLElement;
  console.log(drop);
   
  console.log(dropcover.querySelector('dropdown-part')); // Getting null
  
  setTimeout(function(){
     console.log(dropcover.querySelector('dropdown-part')); // working
  },0);
  </code></pre>