Map<String, Object> source = new HashMap<>();
        source.put("TestKey", "value1");
        source.put("AnotherTestKey", "value2");

        Map<String, Object> nested = new HashMap<>();
        nested.put("NestedKey", "nestedValue");
        source.put("NestedMap", nested);

        Map<String, Object> result = searchLogHelper.toLowerHyphen(source);

        assertEquals("value1", result.get("test_key"));