code: def delete_model(self, identifier, erase=False):
          
          self.delete_object(identifier, erase=erase)
docs: Delete the model with given identifier in the database. Returns the
          handle for the deleted model or None if object identifier is unknown.
  
          Parameters
          ----------
          identifier : string
              Unique model identifier
          erase : Boolean, optinal
              If true, the record will be deleted from the database. Otherwise,
              the active flag will be set to False to support provenance tracking.
  
          Returns
          -------
          ModelHandle