title: get first object in mongoengine
body: <p>I have a class with name of <code>Request</code> and I want to get first object of it in mongoengine 
  I think I can use this :
  <br>first get all objects like this<br> <code>visitors = Request.objects.all()</code><br>and then <br> <code>ss = visitors[0].ip</code><br>
  and then call an attribute of object </p>