I have successfully executed the sample evaluation in jbpm 5.2, I got the processid from processInstance class, so how could i get the userid and taskid for a particular task ?

params.put("employee", "krisv");
            params.put("reason", "Yearly performance evaluation");
            ProcessInstance processInstance = ksession.startProcess("com.sample.evaluation", params);
            long processId = processInstance.getId();
            System.out.println("Process Id"+processId);