RobotsTxt robotsTxt = new RobotsTxt();

        Directive directive = new Directive("MyBot");
        robotsTxt.addDirective(directive);

        Directive retrieved = robotsTxt.getDirective("OtherBot");
        assertNull(retrieved);
    }

    public void test_getDirectiveWithNull() {
        // Test getDirective with null user agent
        RobotsTxt robotsTxt = new RobotsTxt();