// Verify result contains error message
        assertNotNull(result);
        assertTrue(result.contains(errorMessage));
        assertTrue(result.endsWith("\n"));
    }

    public void test_execute_withNullPointerException() {
        // Setup mock SearchLogHelper that throws NullPointerException
        SearchLogHelper mockSearchLogHelper = new SearchLogHelper() {
            @Override
            public void storeSearchLog() {

        assertEquals("custom.document.index", deleteIndex);

        // Assert result is empty when successful
        assertEquals("", result);
    }

    public void test_execute_withNullPointerException() {
        // Create mock SearchEngineClient that throws NullPointerException
        searchEngineClient = new SearchEngineClient() {
            @Override