old_contents: from django.contrib import admin
  from geodj.models import Country, Artist
  
  class CountryAdmin(admin.ModelAdmin):
      list_display = ('name', 'iso_code')
  
  class ArtistAdmin(admin.ModelAdmin):
      list_display = ('name', 'mbid', 'country')
  
  admin.site.register(Country, CountryAdmin)
  admin.site.register(Artist, ArtistAdmin)
  
new_contents: from django.contrib import admin
  from geodj.models import Country, Artist
  
  class CountryAdmin(admin.ModelAdmin):
      list_display = ('name', 'iso_code', 'continent')
  
  class ArtistAdmin(admin.ModelAdmin):
      list_display = ('name', 'mbid', 'country')
  
  admin.site.register(Country, CountryAdmin)
  admin.site.register(Artist, ArtistAdmin)
  
subject: Add continent to admin panel