Assign Human Task to multiple user

How to assign a particular Human task to multiple assignee? Say I have a Human task to be assigned to both John and Mary so that this task comes as result when queried against assignee for both john as well as Mary.
task?assignee=john , task?assignee=mary

Thanks a lot!!

You can set the attribute candidateUsers to many users where each one considered as a candidate for the task.

The user should claim the task to start working on it.