old_contents: from rest_framework import serializers
  
  from peering.models import (
      AutonomousSystem,
      BGPGroup,
      Community,
      Configuration,
      InternetExchange,
      Router,
      RoutingPolicy,
  )
  from utils.api import WritableNestedSerializer
  
  
  class AutonomousSystemNestedSerializer(WritableNestedSerializer):
      url = serializers.HyperlinkedIdentityField(
          view_name="peering-api:autonomoussystem-detail"
      )
  
      class Meta:
          model = AutonomousSystem
          fields = ["id", "url", "asn", "name", "ipv6_max_prefixes", "ipv4_max_prefixes"]
  
  
  class BGPGroupNestedSerializer(WritableNestedSerializer):
      url = serializers.HyperlinkedIdentityField(view_name="peering-api:bgpgroup-detail")
  
      class Meta:
          model = BGPGroup
          fields = ["id", "url", "name", "slug"]
  
  
  class CommunityNestedSerializer(WritableNestedSerializer):
      url = serializers.HyperlinkedIdentityField(view_name="peering-api:community-detail")
  
      class Meta:
          model = Community
          fields = ["id", "url", "name", "slug", "value", "type"]
  
  
  class ConfigurationNestedSerializer(WritableNestedSerializer):
      url = serializers.HyperlinkedIdentityField(
          view_name="peering-api:configuration-detail"
      )
  
      class Meta:
          model = Configuration
          fields = ["id", "url", "name"]
  
  
  class InternetExchangeNestedSerializer(WritableNestedSerializer):
      url = serializers.HyperlinkedIdentityField(
          view_name="peering-api:internetexchange-detail"
      )
  
      class Meta:
          model = InternetExchange
          fields = ["id", "url", "name", "slug"]
  
  
  class RouterNestedSerializer(WritableNestedSerializer):
      url = serializers.HyperlinkedIdentityField(view_name="peering-api:router-detail")
  
      class Meta:
          model = Router
          fields = ["id", "url", "name", "hostname", "platform"]
  
  
  class RoutingPolicyNestedSerializer(WritableNestedSerializer):
      url = serializers.HyperlinkedIdentityField(
          view_name="peering-api:routingpolicy-detail"
      )
  
      class Meta:
          model = RoutingPolicy
          fields = ["id", "url", "name", "slug", "type"]
  
new_contents: from rest_framework import serializers
  
  from peering.models import (
      AutonomousSystem,
      BGPGroup,
      Community,
      Configuration,
      Email,
      InternetExchange,
      Router,
      RoutingPolicy,
  )
  from utils.api import WritableNestedSerializer
  
  
  class AutonomousSystemNestedSerializer(WritableNestedSerializer):
      url = serializers.HyperlinkedIdentityField(
          view_name="peering-api:autonomoussystem-detail"
      )
  
      class Meta:
          model = AutonomousSystem
          fields = ["id", "url", "asn", "name", "ipv6_max_prefixes", "ipv4_max_prefixes"]
  
  
  class BGPGroupNestedSerializer(WritableNestedSerializer):
      url = serializers.HyperlinkedIdentityField(view_name="peering-api:bgpgroup-detail")
  
      class Meta:
          model = BGPGroup
          fields = ["id", "url", "name", "slug"]
  
  
  class CommunityNestedSerializer(WritableNestedSerializer):
      url = serializers.HyperlinkedIdentityField(view_name="peering-api:community-detail")
  
      class Meta:
          model = Community
          fields = ["id", "url", "name", "slug", "value", "type"]
  
  
  class ConfigurationNestedSerializer(WritableNestedSerializer):
      url = serializers.HyperlinkedIdentityField(
          view_name="peering-api:configuration-detail"
      )
  
      class Meta:
          model = Configuration
          fields = ["id", "url", "name"]
  
  
  class EmailNestedSerializer(WritableNestedSerializer):
      url = serializers.HyperlinkedIdentityField(view_name="peering-api:email-detail")
  
      class Meta:
          model = Configuration
          fields = ["id", "url", "name"]
  
  
  class InternetExchangeNestedSerializer(WritableNestedSerializer):
      url = serializers.HyperlinkedIdentityField(
          view_name="peering-api:internetexchange-detail"
      )
  
      class Meta:
          model = InternetExchange
          fields = ["id", "url", "name", "slug"]
  
  
  class RouterNestedSerializer(WritableNestedSerializer):
      url = serializers.HyperlinkedIdentityField(view_name="peering-api:router-detail")
  
      class Meta:
          model = Router
          fields = ["id", "url", "name", "hostname", "platform"]
  
  
  class RoutingPolicyNestedSerializer(WritableNestedSerializer):
      url = serializers.HyperlinkedIdentityField(
          view_name="peering-api:routingpolicy-detail"
      )
  
      class Meta:
          model = RoutingPolicy
          fields = ["id", "url", "name", "slug", "type"]
  
subject: Add API brief version of `Email`