old_contents: from rest_framework import serializers
  from .models import Initiative
  
  class SimpleInitiativeSerializer(serializers.ModelSerializer):
      class Meta:
          model = Initiative
          fields = ["title", "subtitle", "state", "created_at", 
                    "changed_at","summary", "problem", "forderung",
                    "kosten", "fin_vorschlag", "arbeitsweise", "init_argument" ,
                    "einordnung", "ebene", "bereich", "went_public_at",
                    "went_to_discussion_at", "went_to_voting_at", "was_closed_at",
                    # and calculated fields also matter:
                    "slug", "end_of_this_phase"]
  
  
  
new_contents: from rest_framework import serializers
  from .models import Initiative
  
  class SimpleInitiativeSerializer(serializers.ModelSerializer):
      class Meta:
          model = Initiative
          fields = ["id", "title", "subtitle", "state", "created_at",
                    "changed_at","summary", "problem", "forderung",
                    "kosten", "fin_vorschlag", "arbeitsweise", "init_argument" ,
                    "einordnung", "ebene", "bereich", "went_public_at",
                    "went_to_discussion_at", "went_to_voting_at", "was_closed_at",
                    # and calculated fields also matter:
                    "slug", "end_of_this_phase"]
  
  
  
subject: add id to serializer