Zend_Test_PHPUnit_ControllerTestCase和Zend_Layout，在运行测试时无法找到Layout插件

I am starting to write some test cases for controller classes using Zend Framework 1.10.6 and Zend_Test_PHPUnit_ControllerTestCase. I am having problems with one item, which is that while the test cases are running, Zend_Controller_Action_HelperBroker can't find the Layout action helper.I am starting to write some test cases for cont