docs: def delete_model(self, model_or_type, id_=None):
      """Deletes a model.
  
      :model_or_type: if a model, delete that model. If it is a ModelBase subclass, id_ must be
      specified, and the associated record is deleted.
      """
      if not id_:
        constraints = get_model_id_constraints(model_or_type)
      else:
        constraints = get_id_constraints(model_or_type.primary_key_name, id_)
      self.delete(model_or_type.table_name, constraints)
  
      return model_or_type