def __exit__(self, exception_type: Optional[Type[BaseException]], exception_value: Optional[BaseException], traceback: Optional[TracebackType]) -> Optional[bool]:
    self.spark.unpersist()
    return None
def __exit__(self, exception_type: Optional[Type[BaseException]], exception_value: Optional[BaseException], traceback: Optional[TracebackType]) -> Optional[bool]:
    self.spark.unpersist()
    return None