old_contents: from django.contrib import admin
  from .models import DeviceToken, CertFile
  
  
  class DeviceTokenAdmin(admin.ModelAdmin):
      list_display = ('id', 'device_token', 'uuid', 'user')
      list_display_links = ('id', 'device_token', 'uuid', 'user')
  
  admin.site.register(DeviceToken, DeviceTokenAdmin)
  
new_contents: from django.contrib import admin
  from .models import DeviceToken, CertFile
  
  
  class DeviceTokenAdmin(admin.ModelAdmin):
      list_display = ('id', 'device_token', 'uuid', 'user')
      list_display_links = ('id', 'device_token', 'uuid', 'user')
  
  admin.site.register(DeviceToken, DeviceTokenAdmin)
  
  
  class CertFileAdmin(admin.ModelAdmin):
  	list_display = ('id', 'filename', 'target_mode', 'is_use', 'date')
  	list_display_links = ('id', 'filename', 'target_mode')
  
  admin.site.register(CertFile, CertFileAdmin)
  
subject: Add CertFile's model admin site register