def loader(self, db_session, output, clear_workers):
        from dallinger.command_line import LoadSessionRunner
        from dallinger.heroku.tools import HerokuLocalWrapper
        loader = LoadSessionRunner(self.exp_id, output, verbose=True,
                                   exp_config={})
        loader.notify = mock.Mock(return_value=HerokuLocalWrapper.MONITOR_STOP)

        yield loader
    def replay_loader(self, db_session, env, output, clear_workers):
        from dallinger.command_line import LoadSessionRunner
        loader = LoadSessionRunner(self.exp_id,
                                   output,
                                   verbose=True,
                                   exp_config={'replay': True})
        loader.keep_running = mock.Mock(return_value=False)\

        def launch_and_finish(self):
            from dallinger.heroku.tools import HerokuLocalWrapper
            loader.out.log("Launching replay browser...")
            return HerokuLocalWrapper.MONITOR_STOP

        loader.start_replay = mock.Mock(return_value=None,
                                        side_effect=launch_and_finish)
        yield loader