I have a work flow where there is a default transition from task node A to task node B. Unfortunately the users clicked that so the default transition did happen. Now they want to get back to task node A, there is no transition defined to get from B to A. Can I rollback to task node A programmatically ? I tried deleting jbpm_taskinstance and setting the end_ on the prior to null and even changing jbpm_node but did not help. Thanks.