old_contents: from django.contrib.auth.models import User
  from rest_framework import serializers
  
  from api.models import UserPreferences
  
  
  class UserPreferencesSummarySerializer(serializers.HyperlinkedModelSerializer):
      class Meta:
          model = UserPreferences
          fields = (
              'id',
              'url'
          )
  
  
  class UserRelatedField(serializers.PrimaryKeyRelatedField):
  
      def use_pk_only_optimization(self):
          return False
  
      def to_representation(self, value):
          serializer = UserSerializer(value, context=self.context)
          return serializer.data
  
  
  class UserSerializer(serializers.HyperlinkedModelSerializer):
      user_pref = UserPreferencesSummarySerializer(
          source='userpreferences_set',
          many=True)
  
      class Meta:
          model = User
          fields = (
              'id',
              'url',
              'username',
              'first_name',
              'last_name',
              'email',
              'is_staff',
              'is_superuser',
              'date_joined',
              'user_pref'
          )
  
  
  class UserPreferenceSerializer(serializers.HyperlinkedModelSerializer):
      user = UserRelatedField(read_only=True)
  
      class Meta:
          model = UserPreferences
          fields = (
              'id',
              'url',
              'show_beta_interface',
              'user',
              'created_date',
              'modified_date'
          )
  
new_contents: from django.contrib.auth.models import User
  from rest_framework import serializers
  
  from api.models import UserPreferences
  
  
  class UserPreferencesSummarySerializer(serializers.HyperlinkedModelSerializer):
      class Meta:
          model = UserPreferences
          fields = (
              'id',
              'url'
          )
  
  
  class UserRelatedField(serializers.PrimaryKeyRelatedField):
  
      def use_pk_only_optimization(self):
          return False
  
      def to_representation(self, value):
          serializer = UserSerializer(value, context=self.context)
          return serializer.data
  
  
  class UserSerializer(serializers.HyperlinkedModelSerializer):
      user_pref = UserPreferencesSummarySerializer(
          source='userpreferences_set',
          many=True)
  
      class Meta:
          model = User
          fields = (
              'id',
              'url',
              'username',
              'first_name',
              'last_name',
              'email',
              'is_staff',
              'is_superuser',
              'date_joined',
              'user_pref'
          )
  
  
  class UserPreferenceSerializer(serializers.HyperlinkedModelSerializer):
      user = UserRelatedField(read_only=True)
  
      class Meta:
          model = UserPreferences
          fields = (
              'id',
              'url',
              'user',
              'show_beta_interface',
              'airport_ui',
              'created_date',
              'modified_date'
          )
  
subject: Include new airport_ui preference in serializer for view