old_contents: from django.contrib import admin
  
  from mptt.admin import MPTTModelAdmin
  
  from wm.models import *
  
  admin.site.register(Brand)
  admin.site.register(Group, MPTTModelAdmin)
  admin.site.register(Article)
  
new_contents: from django.contrib import admin
  
  from mptt.admin import MPTTModelAdmin
  
  from wm.models import *
  
  admin.site.register(Brand)
  admin.site.register(Group, MPTTModelAdmin)
  admin.site.register(Article)
  admin.site.register(SupplierCode)
  
subject: add supplier codes to admin