new_contents: from django.contrib.auth import get_user_model
  from django.test.testcases import SimpleTestCase
  import django
  
  from djoser.compat import get_user_email_field_name
  from djoser.conf import settings
  
  User = get_user_model()
  
  
  class CompatTestCase(SimpleTestCase):
      def test_get_user_email_field_name_returns_proper_value(self):
          if django.VERSION >= (1, 11):
              email_field_name = User.get_email_field_name()
          else:
              email_field_name = settings.USER_EMAIL_FIELD_NAME
  
          user_email_field_name = get_user_email_field_name(User)
          self.assertEquals(user_email_field_name, email_field_name)
  
subject: Add test for user_email_field_name