init python:
    import threading

    class DollThread(threading.Thread, NoRollback):
        def __init__(self, group=None, target=None, name=None, args=(), kwargs={}, Verbose=None):
            super(DollThread, self).__init__(group, target, name, args, kwargs, Verbose)
            self._return = None

        def run(self):
            try:
                self._return = self._Thread__target(*self._Thread__args, **self._Thread__kwargs)
            except:
                import traceback
                traceback.print_exc()

                if config.developer:
                    raise Exception("Thread just pooped itself.")

            renpy.restart_interaction()

        def join(self, timeout=1):
            threading.Thread.join(self, timeout=timeout)
            return self._return