[chap 3] confuse about argument passed to Controller's constructor

Hi there, I am new to Yii

In chap 3, when performing unit test with repeat function, I see the code:

        public function testRepeat() {

		$message = new MessageController('messageTest');

		$this -> assertEquals('Hello blah sblah', $message -> repeat('Hello blah blah'));

	}

So what is the role of the argument ‘messageTest’ passed to MessageController?

And where is it used?

Thanks

Hi nimbus

Start read the book from the begining. There you find MessageController class.