Docs: lack of example of creating index with fields from a key

From one of our prospects:
Thank you for sharing the syntax to add index with key. I could not find the details of specifying the index to key in the documentation https://docs.hazelcast.org/docs/5.1/javadoc/com/hazelcast/map/IMap.html#addIndex-com.hazelcast.config.IndexType-java.lang.String...- I think it is helpful for clients if you can update the document for 5.2 to include this syntax.