'Setup self.sess (the raw tf.Session)
and self.hooked_sess (the session with hooks and coordinator)'

def _create_session(self):

    hooks = self._callbacks.get_hooks()
    self.sess = self.config.session_creator.create_session()
    self.hooked_sess = tf.train.MonitoredSession(session_creator=ReuseSessionCreator(self.sess), hooks=hooks)
