title: Django Rest-Framework nested serializer order
body: <p>Is there a way to order a nested serializer <code>_set</code>, for example order by <code>pk</code> or <code>time-stamp</code>.</p>
  
  <p>So basically order <code>song_set</code> shown in the json data below from the most recent to the latest object created, in this case by <code>order_by('-timestamp')</code> or <code>order_by('-pk')</code>.</p>
  
  <p><strong>Json data</strong></p>
  
  <pre><code>{
      "pk": 151,
      "album_name": "Name",
      "song_set": [
           {
             pk: 3,
             timestamp: '5 seconds'
           },
           {
             pk: 2,
             timestamp: '10 seconds'
           },
           {
             pk: 1,
             timestamp: '15 seconds'
           }
      ]
  }
  </code></pre>
  
  <p><strong>Model</strong></p>
  
  <pre><code>class Album(models.Model):
      album_name     = models.CharField(max_length=100, blank=True)
  
  
  class Song(models.Model):
      album          = models.ForeignKey('album.Album', default=1)
      timestamp      = models.DateTimeField(auto_now_add=True, auto_now=False)
  </code></pre>
  
  <p><strong>Serializer</strong></p>
  
  <pre><code>class SongListSerializer(HyperlinkedModelSerializer):
      class Meta:
          model = Song
          fields = [
              'pk',
              'timestamp'
          ]
  
  class AlbumSerializer(HyperlinkedModelSerializer):
      song_set = SongListSerializer(many=True, read_only=True)
      class Meta:
          model = Album
          fields = [
              'pk',
              'timestamp',
              'song_set'
          ]
  </code></pre>