title: Webpacker in Rails 6 - Why do some default JS libraries have .start() methods?
body: <p>When creating a new Rails 6 app, packs/application.js automatically includes the following:</p>
  <pre><code>require(&quot;@rails/ujs&quot;).start()
  require(&quot;turbolinks&quot;).start()
  require(&quot;@rails/activestorage&quot;).start()
  require(&quot;channels&quot;)
  </code></pre>
  <p>Why do the top 3 libraries have start methods that need to be manually called?</p>