public function getPluginController($pluginName)
    {
        /*
         * Deprecated.  All controllers should come from the controller manager
         * now and not the service manager.
         *
         * @todo Remove if statement once plugins have been converted.
         */
        if ($this->serviceManager->has($pluginName)) {
            $serviceManager = $this->serviceManager;
        } else {
            $serviceManager = $this->serviceManager->get('ControllerLoader');
        }

        if (!$serviceManager->has($pluginName)) {
            throw new InvalidPluginException(
                "Plugin $pluginName is not loaded or configured. Check
            config/application.config.php"
            );
        }

        $pluginController = $serviceManager->get($pluginName);

        //Plugin controllers must implement this interface
        if (!$pluginController instanceof PluginInterface) {
            throw new InvalidPluginException(
                'Class "' . get_class($pluginController) . '" for plugin "'
                . $pluginName . '" does not implement '
                . '\Rcm\Plugin\PluginInterface'
            );
        }

        return $pluginController;
    }