old_contents: from rest_framework import serializers
  
  from .models import (
      Classroom, DeviceOwner, Facility, FacilityUser, LearnerGroup, Membership,
      Role
  )
  
  
  class FacilityUserSerializer(serializers.ModelSerializer):
  
      class Meta:
          model = FacilityUser
          exclude = ("dataset", "last_login")
          extra_kwargs = {'password': {'write_only': True}}
  
      def create(self, validated_data):
          user = FacilityUser(**validated_data)
          user.set_password(validated_data['password'])
          user.save()
          return user
  
  
  class DeviceOwnerSerializer(serializers.ModelSerializer):
  
      class Meta:
          model = DeviceOwner
          exclude = ("last_login",)
          extra_kwargs = {'password': {'write_only': True}}
  
      def create(self, validated_data):
          user = DeviceOwner(**validated_data)
          user.set_password(validated_data['password'])
          user.save()
          return user
  
  
  class MembershipSerializer(serializers.ModelSerializer):
  
      class Meta:
          model = Membership
          exclude = ("dataset",)
  
  
  class RoleSerializer(serializers.ModelSerializer):
  
      class Meta:
          model = Role
          exclude = ("dataset",)
  
  
  class FacilitySerializer(serializers.ModelSerializer):
  
      class Meta:
          model = Facility
          exclude = ("dataset", "kind", "parent")
  
  
  class ClassroomSerializer(serializers.ModelSerializer):
  
      class Meta:
          model = Classroom
          exclude = ("dataset", "kind")
  
  
  class LearnerGroupSerializer(serializers.ModelSerializer):
  
      class Meta:
          model = LearnerGroup
          exclude = ("dataset", "kind")
  
new_contents: from rest_framework import serializers
  
  from .models import (
      Classroom, DeviceOwner, Facility, FacilityUser, LearnerGroup, Membership,
      Role
  )
  
  
  class FacilityUserSerializer(serializers.ModelSerializer):
  
      class Meta:
          model = FacilityUser
          exclude = ("dataset", "last_login")
          extra_kwargs = {'password': {'write_only': True}}
  
      def create(self, validated_data):
          user = FacilityUser(**validated_data)
          user.set_password(validated_data['password'])
          user.save()
          return user
  
  
  class DeviceOwnerSerializer(serializers.ModelSerializer):
  
      class Meta:
          model = DeviceOwner
          exclude = ("last_login",)
          extra_kwargs = {'password': {'write_only': True}}
  
      def create(self, validated_data):
          user = DeviceOwner(**validated_data)
          user.set_password(validated_data['password'])
          user.save()
          return user
  
  
  class MembershipSerializer(serializers.ModelSerializer):
  
      class Meta:
          model = Membership
          exclude = ("dataset",)
  
  
  class RoleSerializer(serializers.ModelSerializer):
  
      class Meta:
          model = Role
          exclude = ("dataset",)
  
  
  class FacilitySerializer(serializers.ModelSerializer):
  
      class Meta:
          model = Facility
          exclude = ("dataset", "kind", "parent")
  
  
  class ClassroomSerializer(serializers.ModelSerializer):
  
      class Meta:
          model = Classroom
          fields = ('id', 'name', )
  
      def to_representation(self, instance):
          representation = super(ClassroomSerializer, self).to_representation(instance)
          representation['learnerGroups'] = []
          for lg in instance.get_learner_groups():
              representation['learnerGroups'].append({
                  'id': lg.id,
                  'name': lg.name,
              })
          return representation
  
  
  class LearnerGroupSerializer(serializers.ModelSerializer):
  
      class Meta:
          model = LearnerGroup
          exclude = ("dataset", "kind")
  
subject: Add serialized list of learner groups to classroom api