new_contents: from django.contrib.contenttypes.models import ContentType
  from django.test import TestCase, override_settings
  
  from rest_framework import serializers
  
  from dynamic_rest.fields import DynamicHashIdField
  from dynamic_rest.utils import (
      external_id_from_model_and_internal_id,
      internal_id_from_model_and_external_id,
  )
  from tests.models import Dog
  
  
  @override_settings(
      ENABLE_HASHID_FIELDS=True,
      HASHIDS_SALT="I guess you guys aren’t ready for that yet, but your kids are gonna love it.",
  )
  class FieldsTestCase(TestCase):
      def test_dynamic_hash_id_field_with_model_parameter(self):
          class DogModelTestSerializer(serializers.ModelSerializer):
              """
              A custom model serializer simply for testing purposes.
              """
  
              id = DynamicHashIdField(model=Dog)
  
              class Meta:
                  model = Dog
                  fields = ["id", "name", "fur_color", "origin"]
  
          dog = Dog.objects.create(name="Kazan", fur_color="brown", origin="Abuelos")
          serializer = DogModelTestSerializer(dog)
  
          self.assertEqual(
              serializer.data["id"], external_id_from_model_and_internal_id(Dog, dog.id)
          )
  
      def test_dynamic_hash_id_field_without_model_parameter(self):
          class DogModelTestSerializer(serializers.ModelSerializer):
              """
              A custom model serializer simply for testing purposes.
              """
  
              id = DynamicHashIdField()
  
              class Meta:
                  model = Dog
                  fields = ["id", "name", "fur_color", "origin"]
  
          dog = Dog.objects.create(name="Kazan", fur_color="brown", origin="Abuelos")
          serializer = DogModelTestSerializer(dog)
  
          self.assertEqual(
              serializer.data["id"], external_id_from_model_and_internal_id(Dog, dog.id)
          )
  
subject: Add tests for `DynamicHashIdField`