def __init__(self, session_creator, func):
        """
        Args:
            session_creator (tf.train.SessionCreator): a session creator
            func (tf.Session -> tf.Session): takes a session created by
            ``session_creator``, and return a new session to be returned by ``self.create_session``
        """
        self._creator = session_creator
        self._func = func

        Args:
            session_creator (tf.train.SessionCreator): a session creator
            func (tf.Session -> tf.Session): takes a session created by
            ``session_creator``, and return a new session to be returned by ``self.create_session``
        
tensorpack/tfutils/sesscreate.py