Update an existing realm using java client

I came across java library and class that enables to import/create a realm into the server.
Class: org.keycloak.services.managers.RealmManager in keycloak/services library.
But I did not find a method to update an existing realm.
Does it exist in any library? or do I have to write something custom?

Any help is appreciated!

Hi what do you want to update? Normally, you can make updates on the Realm with help of RealmResource.

Thank you for getting back. Yes, I figured out that its doable with REST API resources in keycloak.