old_contents: from django.contrib import admin
  
  from contentcuration.models import Exercise, AssessmentItem, License
  
  admin.site.register(Exercise)
  admin.site.register(AssessmentItem)
  admin.site.register(License)
new_contents: from django.contrib import admin
  
  from contentcuration.models import Exercise, AssessmentItem, License, User
  
  admin.site.register(Exercise)
  admin.site.register(AssessmentItem)
  admin.site.register(License)
  
  class UserAdmin(admin.ModelAdmin):
      list_display = ('first_name', 'last_name', 'email', 'date_joined',)
      date_hierarchy = 'date_joined'
  
  admin.site.register(User, UserAdmin)
subject: Update admin.py to show users in admin portal.