What does $this->dispatch('/') means in zend test

I am writing unit test for zend project, I want to know

<?php

    class IndexControllerTest extends ControllerTestCase
    {

        public function testHomePage() {
            $this->dispatch('/');

        }
    }

The ControllerTestcase.php extends Zend/Test/PHPUnit/ControllerTestCase.php

<?php
    require_once 'Zend/Application.php';
    require_once 'Zend/Test/PHPUnit/ControllerTestCase.php';

    class ControllerTestCase 
        extends Zend_Test_PHPUnit_ControllerTestCase 
    {
        protected $application;

        public function setUp() {
            $this->bootstrap = array($this,'appBootstrap');
            parent::setUp();

        }

        public function appBootstrap() {
            $this->application = 
                开发者_高级运维new Zend_Application(APPLICATION_ENV,
                                     APPLICATION_PATH.'/configs/application.ini');

            $this->application->bootstrap();


        }
    }

what does $this->dispatch('/'); means? does this mean forward to request to root of the application?

From comment to this method:

 * Dispatch the MVC
 *
 * If a URL is provided, sets it as the request URI in the request object.
 * Then sets test case request and response objects in front controller,
 * disables throwing exceptions, and disables returning the response.
 * Finally, dispatches the front controller.  

http://framework.zend.com/svn/framework/standard/tags/release-1.9.8/library/Zend/Test/PHPUnit/ControllerTestCase.php

In object oriented programming, when a class extends another, it inherits the methods (or functions) of its parent class (the class it is extending).

You can use $this->method to call a classes methods from within itself or its descendents (other classes that extend it).

given that dispatch is not defined in IndexControllerTest, it must be a function of ControllerTestCase (which IndexControllerTest extends) and it is passing the string '/' to it.

Have a look for the class ControllerTestCase and there will be a function called dispatch, you can see what that is doing there.