title: Pass arguments to serializer DRF
body: <p>Well I'm struggling at sending arguments to the serializer class, my code looks like:</p>
  
  <p><strong>models.py</strong></p>
  
  <pre><code>class Transaction(models.Model):
      owner = models.ForeignKey(User, on_delete=models.SET("DELETED"), related_name='transactions')
      date = models.DateField(auto_now_add=True)
      concept = models.CharField(max_length=100)
      value = models.DecimalField(max_digits=10, decimal_places=2)
      total = models.DecimalField(max_digits=10, decimal_places=2)
  </code></pre>
  
  <p><strong>serializers.py</strong> </p>
  
  <pre><code>class TransactionSerializer(serializers.ModelSerializer):
      total = serializers.ReadOnlyField(source='new_total')
      owner = serializers.ReadOnlyField(source='owner.username')
  
      class Meta:
          model = Transaction
          fields = '__all__'
  </code></pre>
  
  <p><strong>views.py</strong></p>
  
  <pre><code>class TransactionHandler(viewsets.ModelViewSet):
      queryset = Transaction.objects.all()
      serializer_class = TransactionSerializer
  
      def perform_create(self, serializer):
          last_transaction = Transaction.objects.latest('id')
          new_total = last_transaction.total + Decimal(self.request.data['value'])
          serializer.save(owner=self.request.user, new_total=new_total)
  </code></pre>
  
  <p>When in the serializer.save() method there is only the owner argument all works fine but when I add the second argument all gets messy</p>