code: def delete(self, using=None, soft=True, *args, **kwargs):
          
          if soft:
              self.is_removed = True
              self.save(using=using)
          else:
              return super(SoftDeletableModel, self).delete(using=using, *args, **kwargs)
docs: Soft delete object (set its ``is_removed`` field to True).
          Actually delete object if setting ``soft`` to False.