Thank you for your prompt responses. What I am actually try to do is when user claims a task, I want to be able to figure out which other tasks exists/remains open from that pool, and close them. My expectation was that when one user claims a task from a pool, other tasks are deleted or completed, most probably completed because deletion will throw me an exception. Now, another issue is if I manually close the tasks, it will go a step further in my process and generate another user task. So, that doesn't help. I tried using "deleteUserIdentityLink" to remove any association with the task at hand, I am not sure if this is the right approach.
I will try to create a JIRA ticket soon, we need unit tests along with it right ?