title: Disable users from claiming - Activiti Task
body: <p>I have a task which can be assigned to Candidate group user's CG1. Now there are 10 user in CG1 but based on few criteria i want to exclude one user of this 10. So the excluded user should not able to see the task when queried for tasks for assignment</p>
  
  <pre><code>I used delegateTask.deleteCandidateUser(userId) on the creation of the task.
  </code></pre>
  
  <p>But the above did not work. Please advice.</p>