def on_cleanup_error(function, path, excinfo):
                click.secho("warning: failed to remove file or directory: {}\n"
                            "please delete it manually.".format(path),
                            fg="red")
def active_at_datetime(self, deadline):
        """Check whether the verification was active at a particular datetime.

        Arguments:
            deadline (datetime): The date at which the verification was active
                (created before and expiration datetime is after today).

        Returns:
            bool

        """
        return (
            self.created_at < deadline and
            self.expiration_datetime > now()
        )