Missing Method in CobaltController

Error: The action robots.txt is not defined in controller CobaltController

Error: Create CobaltController::robots.txt() in file: app/controllers/cobalt_controller.php.

<?php
class CobaltController extends AppController {

	var $name = 'Cobalt';


	function robots.txt() {

	}

}
?>

Notice: If you want to customize this error message, create app/views/errors/missing_action.ctp.