title: Can to_representation() in Django Rest Framework access the normal fields
body: <p>The docs on using <code>to_representation</code> is somewhat short.  This method is used by <code>Django Rest Framework 3.0+</code> to change the representation of your data in an API.</p>
  
  <p>Here' the documentation link:</p>
  
  <p><a href="http://www.django-rest-framework.org/api-guide/serializers/#overriding-serialization-and-deserialization-behavior" rel="noreferrer">http://www.django-rest-framework.org/api-guide/serializers/#overriding-serialization-and-deserialization-behavior</a></p>
  
  <p>Here is my current code:</p>
  
  <pre><code>from django.forms.models import model_to_dict
  
  class PersonListSerializer(serializers.ModelSerializer):
  
      class Meta:
          model = Person
          fields = ('foo', 'bar',)
  
      def to_representation(self, instance):
          return model_to_dict(instance)
  </code></pre>
  
  <p>When I do this code, it returns all fields in the model instead of the fields that I have specified above in <code>class Meta: fields</code>.</p>
  
  <p>Is it possible to reference the <code>class Meta: fields</code> within the <code>to_representation</code> method?</p>