SovBundle/DependencyInjection/Configuration.php

<?php

namespace Lc\SovBundle\DependencyInjection;

use Symfony\Component\Config\Definition\Builder\TreeBuilder;
use Symfony\Component\Config\Definition\ConfigurationInterface;

/**
 * This is the class that validates and merges configuration from your app/config files
 *
 * To learn more see {@link http://symfony.com/doc/current/cookbook/bundles/extension.html#cookbook-bundles-extension-config-class}
 */
class Configuration implements ConfigurationInterface
{
        /**
         * {@inheritdoc}
         */
        public function getConfigTreeBuilder()
        {
                $treeBuilder = new TreeBuilder('lc_admin');
                $rootNode = $treeBuilder->getRootNode();

                $rootNode
                        ->children()
                        ->scalarNode('dashboardDefault')->defaultValue('App\Controller\Admin\DashboardController')->end()
                        ->end();


                return $treeBuilder;
        }
}