title: Django REST Framework serializer validation
body: <p>How exactly do I use validators in my serializers? I have currently create my validators in <code>app/validators.py</code> and have my serializers in <code>app/serializers.py</code>.</p>
  
  <pre><code>class OrderItemSerializer(serializers.ModelSerializer):
      item_id = serializers.IntegerField()
      item_date = serializers.DateTimeField()
      ...
  
      class Meta:
          model = Item
          validators = [validate_item_date]
          fields = ('item_id', 'item_date')
  
  from rest_framework.serializers import ValidationError
  </code></pre>
  
  <p>validators.py</p>
  
  <pre><code>def validate_item_date(item_date):
      if item_date &lt; {something}:
          raise ValidationError('')
  </code></pre>
  
  <p>My question basically: do I provide the <code>item_date</code> as parameter here or does it not work like this?</p>