successor.py

    def set_workflow_state(self):
        state = 'task-state-new-successor'
        mtool = getToolByName(self.context, 'portal_membership')
        wtool = getToolByName(self.context, 'portal_workflow')
        current_user_id = mtool.getAuthenticatedMember().getId()
        wf_ids = wtool.getChainFor(self.context)
        if wf_ids:
            wf_id = wf_ids[0]
            comment = 'Created successor.'
            wtool.setStatusOf(wf_id, self.context, {'review_state': state,
                                                    'action' : state,
                                                    'actor': current_user_id,
                                                    'time': DateTime(),
                                                    'comments': comment,})