old_contents: from rest_framework import serializers
  
  from agir.events.serializers import EventSerializer
  from agir.groups.serializers import SupportGroupSerializer
  from agir.lib.serializers import FlexibleFieldsMixin
  from agir.people.serializers import PersonSerializer
  
  
  class ActivitySerializer(FlexibleFieldsMixin, serializers.Serializer):
      id = serializers.CharField()
      type = serializers.CharField()
      subtype = serializers.CharField(source="type")
  
      timestamp = serializers.DateTimeField()
  
      event = EventSerializer(
          fields=[
              "id",
              "name",
              "startTime",
              "endTime",
              "participantCount",
              "illustration",
              "schedule",
              "location",
              "rsvp",
              "routes",
          ]
      )
      supportGroup = SupportGroupSerializer(source="supportgroup", fields=["name", "url"])
      individual = PersonSerializer(fields=["fullName"])
  
      status = serializers.CharField()
  
new_contents: from rest_framework import serializers
  
  from agir.events.serializers import EventSerializer
  from agir.groups.serializers import SupportGroupSerializer
  from agir.lib.serializers import FlexibleFieldsMixin
  from agir.people.serializers import PersonSerializer
  
  
  class ActivitySerializer(FlexibleFieldsMixin, serializers.Serializer):
      id = serializers.CharField()
      type = serializers.CharField()
      subtype = serializers.CharField(source="type")
  
      timestamp = serializers.DateTimeField()
  
      event = EventSerializer(
          fields=[
              "id",
              "name",
              "startTime",
              "endTime",
              "participantCount",
              "illustration",
              "schedule",
              "location",
              "rsvp",
              "routes",
          ]
      )
      supportGroup = SupportGroupSerializer(source="supportgroup", fields=["name", "url"])
      individual = PersonSerializer(fields=["fullName", "email"])
  
      status = serializers.CharField()
  
subject: Add individual email field to activity serializer