title: AttributeError: 'list' object has no attribute 'order_by'
body: <p>I was trying to combine two <code>queryset</code> objects by <code>itertools chain</code> python predefine function and filter this with <code>order_by</code>. but i'm getting an <code>AttributeError</code>: <code>'list' object has no attribute 'order_by'</code>.<br>
  If anybody could figure out where i'm doing thing wrong then would be much appreciated. thank you so much in advance.</p>
  <p>views.py :</p>
  <pre><code>try:
      qs = Conversation.objects.filter(
          Q(chat__from_user=user) &amp;
          Q(chat__to_user=to_user))
  
      qs_2 = Conversation.objects.filter(
          Q(chat__from_user=to_user) &amp;
          Q(chat__to_user=user))
  except:
      raise ValidationError({&quot;message&quot;:&quot;bad request&quot;})
  
  all_qs = list(chain(qs, qs_2)).order_by('-created_on')
  
  </code></pre>