old_contents: from django.contrib import admin
  from django.contrib.auth import get_user_model
  
  # DJANGAE
  from djangae.contrib.gauth.models import (
      GaeUser,
      GaeDatastoreUser,
      Group,
      PermissionsMixin,
  )
  
  user_model = get_user_model()
  
  # Only register the user model with the admin if it is a Djangae model.  If a different/custom user
  # model is in use, then allow that app to deal with the Django admin.
  
  if user_model in (GaeUser, GaeDatastoreUser):
      # Note that we don't need Django's usual custom Admin class with the password change form because
      # users created through the App Engine users API do not have passwords stored in our DB.
      admin.site.register(user_model)
  
  
  # Only register the Group model if the User model is one of the Datastore-based ones (i.e. one
  # which uses the Datastore permissions)
  
  if isinstance(user_model, PermissionsMixin):
      admin.site.register(Group)
  
new_contents: from django.contrib import admin
  from django.contrib.auth import get_user_model
  
  # DJANGAE
  from djangae.contrib.gauth.models import (
      GaeUser,
      GaeDatastoreUser,
      Group,
      PermissionsMixin,
  )
  
  user_model = get_user_model()
  
  # Only register the user model with the admin if it is a Djangae model.  If a different/custom user
  # model is in use, then allow that app to deal with the Django admin.
  
  if user_model in (GaeUser, GaeDatastoreUser):
      # Note that we don't need Django's usual custom Admin class with the password change form because
      # users created through the App Engine users API do not have passwords stored in our DB.
      admin.site.register(user_model)
  
  
  # Only register the Group model if the User model is one of the Datastore-based ones (i.e. one
  # which uses the Datastore permissions)
  
  if issubclass(user_model, PermissionsMixin):
      admin.site.register(Group)
  
subject: Fix a bug that would prevent Groups being displayed in the admin