code: public function registerController($controller, $applicationName = 'default')
      {
      	if ( !$controller instanceof \Nkey\Caribu\Mvc\Controller\AbstractController ) {
  	        if (! class_exists($controller)) {
  	            throw new ControllerException("No such controller class {controller} found", array(
  	                'controller' => $controller
  	            ));
  	        }
  	        $c = new $controller();
  	        if (! ($c instanceof AbstractController)) {
  	            throw new ControllerException("Controller {controller} is not in application scope", array(
  	                'controller' => $controller
  	            ));
  	        }
      	}
          else {
          	$c = $controller;
          }
          $settings = $c->getControllerSettings();
          $this->controllers[$applicationName][$settings->getControllerSimpleName()] = $settings;
          
          return $this;
      }
docs: Register a new controller class
  
  @param string $controller
  The full qualified name of controller class to register
  @param string $applicationName
  Optional name of application where controller will be registered in
  
  @return Application Current application instance
  
  @throws ControllerException