public static function assertTrue($actual, string $message = '')
    {
        self::$count += 1;

        if ((bool)$actual) {
            return;
        }

        if (!$message) {
            $message = sprintf(
                'Failed asserting that %s is truthy',
                var_export($actual, true)
            );
        }
        throw new AssertionError($message);
    }