title: Django rest framework: override create() in ModelSerializer passing an extra parameter
body: <p>I am looking for a way to properly ovverride the default <code>.create()</code> method of a <code>ModelSerializer</code> serializer in Django Rest Framework for dealing with an extra parameter.</p>
  
  <p>In my original Django model I have just overridden the default<code>.save()</code> method for managing an <code>extra</code> param. Now <code>.save()</code> can be called also in this way: <code>.save(extra = 'foo')</code>.</p>
  
  <p>I have to create a <code>ModelSerializer</code> mapping on that original Django model:</p>
  
  <pre><code>from OriginalModels.models import OriginalModel
  from rest_framework import serializers
  
  class OriginalModelSerializer(serializers.ModelSerializer):
  
      # model fields
      class Meta:
          model = OriginalModel
  </code></pre>
  
  <p>But in this way I can't pass the <code>extra</code> param to the model <code>.save()</code> method.</p>
  
  <p>How can I properly override the <code>.create()</code> method of my <code>OriginalModelSerializer</code> class to take (eventually) this <code>extra</code> param into account?</p>