human
Solve the following python programming problem given the following code:
@connect_on_app_finalize
def add_accumulate_task(app):
assistant
#Here is the Python program you requested.

    """Task used by Task.replace when replacing task with group.
    """
    @app.task(bind=True, name=u'celery.accumulate', shared=False, lazy=False)
    def accumulate(self, *args, **kwargs):
        index = kwargs.get(u'index')
        return (args[index] if (index is not None) else args)
    return accumulate