title: Puppeteer - page.$$('').length returns undefined
body: <p>I was having errors with my code, so i tried to log the value in the erroneous code. So i did:</p>
  
  <pre><code>const read = await page.$$('.Ns6lhs9 _gfh3').length;
  </code></pre>
  
  <p>Then i <code>console.log(read);</code></p>
  
  <p>For some reason i get <code>undefined</code> although there are elements with class name <code>'Ns6lhs9 _gfh3'</code> in the HTML</p>