text: from market.core import serializers
  
  
  class CartSerializer(serializers.ModelSerializer):
      """Dive into its items."""
  
      class Meta:
          """Serializer options."""
          depth = 1
          fields = ('created', 'modified', 'items')
  
  
  class CartItemSerializer(serializers.ModelSerializer):
      """Serialize everything but back-reference to Cart."""
  
      class Meta:
          """Serializer options."""
          depth = 0
          fields = ('quantity', 'item')
  