def METHOD_NAME(self, instance_id):
    """
    Retrieve a model corresponding at given ID and return it as a JSON
    object.
    """
    try:
        instance = tasks_service.get_comment_with_relations(instance_id)
        self.check_read_permissions(instance)
        result = self.clean_get_result(instance)
    except StatementError as exception:
        current_app.logger.error(str(exception), exc_info=1)
        return {"message": str(exception)}, 400
    except ValueError:
        raise CommentNotFoundException
    return result, 200