// Test getDirective when directive doesn't exist
        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

     * @return The Directive object matching the user agent, or null if no matching directive is found or if userAgent is null
     */
    public Directive getDirective(final String userAgent) {
        if (userAgent == null) {
            return null;
        }
        for (final Directive directive : directiveMap.values()) {

                        // Normalize user-agent to lowercase
                        final String userAgent = value.toLowerCase(Locale.ENGLISH);
                        Directive currentDirective = robotsTxt.getDirective(userAgent);
                        if (currentDirective == null) {
                            currentDirective = new Directive(userAgent);
                            robotsTxt.addDirective(currentDirective);

        assertTrue(robotsTxt.allows("/orphaned2/", "AnyBot"));

        // Test GoodBot - should parse valid directives and ignore invalid ones
        assertNotNull(robotsTxt.getDirective("goodbot"));
        assertFalse(robotsTxt.allows("/admin/", "GoodBot"));
        assertTrue(robotsTxt.allows("/public/", "GoodBot"));
        // Invalid directives should not cause parsing to fail