      def natural_key(self):
          return (self.kind, self.name)
  
  
  @python_2_unicode_compatible
  class Category(models.Model):
      name = models.CharField(max_length=20)
      meta_data = models.ForeignKey(CategoryMetaData, models.SET_NULL, null=True, default=None)
  
      class Meta:
 
</s> remove @python_2_unicode_compatible
 </s> add  </s> remove @python_2_unicode_compatible
 </s> add  </s> remove @python_2_unicode_compatible
 </s> add  </s> remove @python_2_unicode_compatible
 </s> add  </s> remove @python_2_unicode_compatible
 </s> add 
      def natural_key(self):
          return (self.kind, self.name)
  
  

  class Category(models.Model):
      name = models.CharField(max_length=20)
      meta_data = models.ForeignKey(CategoryMetaData, models.SET_NULL, null=True, default=None)
  
      class Meta:
keep keep keep keep replace keep keep keep keep keep
 Refs #23919 -- Removed python_2_unicode_compatible decorator usage 
tests/serializers/models/base.py