old_contents: from django.contrib.auth import authenticate, get_user_model
  
  import pytest
  from users.models import User
  from users.managers import UserManager
  
  
  def test_that_get_user_model_returns_correct_model():
      assert get_user_model() == User
  
  @pytest.mark.django_db
  def test_user_manager():
      assert isinstance(User.objects, UserManager)
  
  
  @pytest.mark.django_db
  def test_create_user_and_authenticate():
      user = User.objects.create_user('lennon@thebeatles.com', 'johnpassword')
  
      authenticated_user = authenticate(
          username='lennon@thebeatles.com',
          password='johnpassword'
      )
  
      assert user == authenticated_user
  
new_contents: from django.contrib.auth import authenticate, get_user_model
  
  import pytest
  from users.models import User
  from users.managers import UserManager
  
  
  def test_that_get_user_model_returns_correct_model():
      assert get_user_model() == User
  
  @pytest.mark.django_db
  def test_user_manager():
      assert isinstance(User.objects, UserManager)
  
  
  @pytest.mark.django_db
  def test_create_user_and_authenticate():
      user = User.objects.create_user('lennon@thebeatles.com', 'johnpassword')
  
      authenticated_user = authenticate(
          username='lennon@thebeatles.com',
          password='johnpassword'
      )
  
      assert user == authenticated_user
  
  @pytest.mark.django_db
  def test_user_get_short_name():
      user = User.objects.create_user('lennon@thebeatles.com', 'johnpassword')
  
      assert 'lennon@thebeatles.com' == user.get_short_name()
  
subject: add test for models