full workflow definition

 <userTask id="reviewTask" name="Review Task"
            activiti:formKey="wf:activitiReviewTask">
           <extensionElements>
               <activiti:taskListener event="create" class="org.alfresco.repo.workflow.activiti.tasklistener.ScriptTaskListener">
                  <activiti:field name="script">
                     <activiti:string>
                        if (typeof bpm_workflowDueDate != 'undefined') task.dueDate = bpm_workflowDueDate
                        if (typeof bpm_workflowPriority != 'undefined') task.priority = bpm_workflowPriority;
                     </activiti:string>
                  </activiti:field>
               </activiti:taskListener>
               <activiti:taskListener event="complete" class="org.alfresco.repo.workflow.activiti.tasklistener.ScriptTaskListener">
			   <runas>admin</runas>
                  <activiti:field name="script">
				  <variable name="bpm_assignee" access="write" />
                    <variable name="bpm_package" access="read" />
                     <activiti:string>
                       	execution.setVariable('wf_reviewOutcome', task.getVariable('wf_reviewOutcome'));

for (var i = 0; i < bpm_package.children.length; i++)
{
           var resource = bpm_package.children[i];
           resource.takeOwnership();
           resource.setInheritsPermissions(false);
           resource.setPermission("Read", task.getOwner());
           resource.setOwner(task.getAssignee());
 }



                     </activiti:string>
                  </activiti:field>
               </activiti:taskListener>
           </extensionElements>
            <humanPerformer>
                <resourceAssignmentExpression>
                    <formalExpression>${bpm_assignee.properties.userName}</formalExpression>
                </resourceAssignmentExpression>
            </humanPerformer>
        </userTask>