old_contents: from core.models.request import QuotaRequest
  from core.models.status_type import StatusType
  from core.models.user import AtmosphereUser
  from rest_framework import serializers
  
  
  class QuotaRequestSerializer(serializers.ModelSerializer):
      id = serializers.CharField(read_only=True, source="uuid", required=False)
      created_by = serializers.SlugRelatedField(
          slug_field='username', source='created_by',
          queryset=AtmosphereUser.objects.all())
      status = serializers.SlugRelatedField(
          slug_field='name', source='status',
          queryset=StatusType.objects.all())
  
      class Meta:
          model = QuotaRequest
          exclude = ('uuid', 'membership')
new_contents: from core.models.request import QuotaRequest
  from core.models.status_type import StatusType
  from core.models.user import AtmosphereUser
  from rest_framework import serializers
  
  
  class QuotaRequestSerializer(serializers.ModelSerializer):
      id = serializers.CharField(read_only=True, source="uuid", required=False)
      created_by = serializers.SlugRelatedField(
          slug_field='username',
          queryset=AtmosphereUser.objects.all())
      status = serializers.SlugRelatedField(
          slug_field='name',
          queryset=StatusType.objects.all())
  
      class Meta:
          model = QuotaRequest
          exclude = ('uuid', 'membership')
subject: fix DRF3 error source matching the field name