title: how can I render laravel mailable to variable
body: <p>I need to get the html of a Mailable class</p>
  
  <pre><code>$mail-&gt;html = (new InactivityReminder())-&gt;"do something to output the html"
  </code></pre>
  
  <p>There seems to be no toHtml method or something similar.</p>
  
  <p>Mailable:</p>
  
  <pre><code>class InactivityReminder extends Mailable
  {
      use Queueable, SerializesModels;
  
      public function __construct()
      {
  
      }
  
      public function build()
      {
          return $this-&gt;markdown('mail.it.inactivityReminder');
      }
  }
  </code></pre>