code: def app_in_list(self, app_label, apps_list):
          
          appconfig = django_apps.get_app_config(app_label)
          appconfig_full_name = '{}.{}'.format(
              appconfig.__module__, appconfig.__class__.__name__)
          return (appconfig.name in apps_list) or (appconfig_full_name in apps_list)
docs: Is 'app_label' present in 'apps_list'?
  
          apps_list is either settings.SHARED_APPS or settings.TENANT_APPS, a
          list of app names.
  
          We check the presence of the app's name or the full path to the apps's
          AppConfig class.
          https://docs.djangoproject.com/en/1.8/ref/applications/#configuring-applications