def delete(self, doc):
        if doc.id is None:
            raise DatabaseException('Document does not have id')
        if doc.sid is None:
            try:
                rs = self.db.docs.remove({'id': doc.id}, safe=True)
                assert rs['n'] == 1
            except Exception as e:
                raise DatabaseException(e)
            return None
        doc.data = None
        return self.update(doc)
def profile(self, action_name: str) -> Generator:
        """
        Yields a context manager to encapsulate the scope of a profiled action.

        Example::

            with self.profile('load training data'):
                # load training data code

        The profiler will start once you've entered the context and will automatically
        stop once you exit the code block.
        """
        try:
            self.start(action_name)
            yield action_name
        finally:
            self.stop(action_name)