code: def validate_admin_registration(cls, model):
      
  
      if not is_multilingual_model(model):
          return
  
      from django.contrib.admin.validation import check_isdict, check_isseq
  
      opts = model._meta
  
      # this is heavily based on django.contrib.admin.validation.
      if hasattr(cls, '_dm_prepopulated_fields'):
          check_isdict(cls, '_dm_prepopulated_fields', cls.prepopulated_fields)
          for field, val in cls._dm_prepopulated_fields.items():
              f = get_field(cls, model, opts, 'prepopulated_fields', field)
              if isinstance(f, (models.DateTimeField, models.ForeignKey,
                  models.ManyToManyField)):
                  raise ImproperlyConfigured("'%s.prepopulated_fields['%s']' "
                          "is either a DateTimeField, ForeignKey or "
                          "ManyToManyField. This isn't allowed."
                          % (cls.__name__, field))
              check_isseq(cls, "prepopulated_fields['%s']" % field, val)
              for idx, f in enumerate(val):
                  get_field(cls, model,
                          opts, "prepopulated_fields['%s'][%d]"
                          % (f, idx), f)
docs: Validates a class specified as a model admin.
  
      Right now this means validating prepopulated_fields, as for
      multilingual models DM handles them by itself.