* Typically used when a document or resource is not available during crawling or indexing.
 */
public class ContentNotFoundException extends FessSystemException {

    private static final long serialVersionUID = 1L;

    /**
     * Constructs a new ContentNotFoundException with the specified parent URL and URL.
     *
     * @param parentUrl the URL of the parent document

    }

    @Test
    public void test_instanceOfFessSystemException() {
        // Verify that ContentNotFoundException is an instance of FessSystemException
        String parentUrl = "http://example.com/parent";
        String url = "http://example.com/child";
        ContentNotFoundException exception = new ContentNotFoundException(parentUrl, url);

        assertTrue(exception instanceof FessSystemException);

            final FailureUrlService failureUrlService = ComponentUtil.getComponent(FailureUrlService.class);
            failureUrlService.store(crawlingConfig, ContentNotFoundException.class.getCanonicalName(), url,
                    new ContentNotFoundException(urlQueue.getParentUrl(), url));
        }
    }

    /**
     * Stores a child URL in the crawling queue with duplicate host handling.