old_contents: from rest_framework import serializers
  
  from .models import Service, Category, ServicePhoto
  
  
  class CategorySerializer(serializers.ModelSerializer):
      class Meta:
          model = Category
          fields = ('id', 'name', 'photo', 'order')
  
  
  class ServicePhotoSerializer(serializers.ModelSerializer):
      """
      """
      class Meta:
          model = ServicePhoto
          fields = ('id', 'photo')
  
  
  class ServiceSerializer(serializers.ModelSerializer):
      """ Usage:
          from rest_framework.renderers import JSONRenderer
          from semillas_backend.users.serializers import UserSerializer
  
          JSONRenderer().render(UserSerializer(user_instance).data)
      """
      category = CategorySerializer()
      photos = ServicePhotoSerializer(many=True)
      class Meta:
          model = Service
          fields = ('id', 'title', 'date', 'description', 'category', 'photos')
  
new_contents: from rest_framework import serializers
  
  from .models import Service, Category, ServicePhoto
  from semillas_backend.users.serializers import UserSerializer
  
  
  class CategorySerializer(serializers.ModelSerializer):
      class Meta:
          model = Category
          fields = ('id', 'name', 'photo', 'order')
  
  
  class ServicePhotoSerializer(serializers.ModelSerializer):
      """
      """
      class Meta:
          model = ServicePhoto
          fields = ('id', 'photo')
  
  
  class ServiceSerializer(serializers.ModelSerializer):
      """ Usage:
          from rest_framework.renderers import JSONRenderer
          from semillas_backend.users.serializers import UserSerializer
  
          JSONRenderer().render(UserSerializer(user_instance).data)
      """
      category = CategorySerializer()
      photos = ServicePhotoSerializer(many=True)
      author = UserSerializer()
      class Meta:
          model = Service
          fields = ('id', 'title', 'date', 'description', 'author', 'category', 'photos')
  
subject: Add user serialized to ServiceSerializer