// Should return null when no clauses are added
        assertNull(result);
    }

    // Test convertBooleanQuery with nested BooleanQuery
    @Test
    public void test_convertBooleanQuery_withNestedBooleanQuery() {
        // Create inner BooleanQuery
        BooleanQuery.Builder innerBoolQueryBuilder = new BooleanQuery.Builder();
        TermQuery innerTermQuery = new TermQuery(new Term("innerField", "innerValue"));