def METHOD_NAME(
    self, exception: BaseException, unused_debug_mode: bool
) -> None:
    """Handles exceptions raised by this handler.
    Args:
        exception: Exception. The exception raised by the handler.
        unused_debug_mode: bool. Whether the app is running in debug mode.
    """
    if isinstance(exception, self.InvalidInputException):
        (
            _,
            _,
            classroom_url_fragment,
            topic_url_fragment,
            _,
            _
        ) = self.request.path.split('/')
        self.redirect(
            '/learn/%s/%s/practice' % (
                classroom_url_fragment, topic_url_fragment
            )
        )
        return
    super().METHOD_NAME(exception, unused_debug_mode)