old_contents: from django.contrib import admin
  from mailwhimp.models import Campaign, List, Application
  
  admin.site.register(Application)
  admin.site.register(List)
  admin.site.register(Campaign)
new_contents: from django.contrib import admin
  from mailwhimp.models import Campaign, List, Application
  
  
  class ApplicationAdmin(admin.ModelAdmin):
      actions = ['load_lists']
  
      def load_lists(self, request, queryset):
          for application in queryset.all():
              application.load_lists()
  
  
  admin.site.register(Application, ApplicationAdmin)
  admin.site.register(List)
  admin.site.register(Campaign)
subject: Load lists through admin