code: @Deployment public void testSequentialServiceTaskWithClassAndCollection(){
    Collection<Integer> items=Arrays.asList(1,2,3,4,5,6);
    Map<String,Object> vars=new HashMap<String,Object>();
    vars.put("result",1);
    vars.put("items",items);
    ProcessInstance procInst=runtimeService.startProcessInstanceByKey("multiInstanceServiceTask",vars);
    Integer result=(Integer)runtimeService.getVariable(procInst.getId(),"result");
    assertEquals(720,result.intValue());
    Execution waitExecution=runtimeService.createExecutionQuery().processInstanceId(procInst.getId()).activityId("wait").singleResult();
    runtimeService.trigger(waitExecution.getId());
    assertProcessEnded(procInst.getId());
  }
  