docs: def to_internal_value(self, data):
          """Basically, each author dict must include either a username or id."""
          # model = get_user_model()
          model = self.Meta.model
  
          if "id" in data:
              author = model.objects.get(id=data["id"])
          else:
              if "username" not in data:
                  raise ValidationError("Authors must include an ID or a username.")
              username = data["username"]
              author = model.objects.get(username=username)
          return author