@Override
            public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
                // This may cause IOException due to OpenSearch XContent complexity
                builder.startObject();
                builder.field("string", "test");
                builder.endObject();
                return builder;
            }
        };

        try {

        Map<String, String> complexObject = new HashMap<>();
        complexObject.put("nested", "value");

        dataStoreParams.put("complexKey", complexObject);
        assertEquals(complexObject, dataStoreParams.get("complexKey"));

        String asString = dataStoreParams.getAsString("complexKey");
        assertNotNull(asString);
        assertTrue(asString.contains("nested"));
    }

    // Test overwriting existing values