init python:
    import threading

    class DollThread(threading.Thread, NoRollback):
        def __init__(self, group=None, target=None, name=None, args=(), kwargs=None, *, daemon=None):
            threading.Thread.__init__(self, group, target, name, args, kwargs, daemon=daemon)

            self._return = None

        def run(self):
            if self._target is not None:
                self._return = self._target(*self._args, **self._kwargs)

            renpy.restart_interaction()

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