UpdateRequest in 0.19.2

Hi.
I want to use java api to perform document update.
But I can not make it work from java.
My code:
...
import org.elasticsearch.action.update.UpdateRequest;
...
UpdateRequest request = client.prepareUpdate().setIndex("users")
.setType("user").setId(id).setScript(script)
.request();
client.update(request);

...
When I post my script with use of Http standard libraries it works, the document is updated.
Can someone explain how to use UpdateRequest ?
BR