text: import pytest
  from django.contrib.admin.sites import AdminSite
  from mixer.backend.django import mixer
  from .. import admin
  from .. import models
  pytestmark = pytest.mark.django_db
  
  
  class TestPostAdmin:
      def test_excerpt(self):
          site = AdminSite()
          post_admin = admin.PostAdmin(models.Post, site)
          obj = mixer.blend('comments.Post', body='Hello World')
  
          result = post_admin.excerpt(obj)
          expected = obj.get_excerpt(5)
          assert result == expected, ('Should return the result form the .excerpt() function')