src/Mcfedr/AwsPushBundle/DependencyInjection/Configuration.php
public function getConfigTreeBuilder()
    {
        $treeBuilder = new TreeBuilder('mcfedr_aws_push');

        if (method_exists($treeBuilder, 'getRootNode')) {
            $rootNode = $treeBuilder->getRootNode();
        } else {
            // BC layer for symfony/config 4.1 and older
            $rootNode = $treeBuilder->root('mcfedr_aws_push');
        }

        $rootNode
            ->children()
                ->arrayNode('aws')
                    ->children()
                        ->variableNode('credentials')->end()
                        ->scalarNode('key')->cannotBeEmpty()->setDeprecated('The "%node%" option is deprecated. Use "credentials" instead.')->end()
                        ->scalarNode('secret')->cannotBeEmpty()->setDeprecated('The "%node%" option is deprecated. Use "credentials" instead.')->end()
                        ->scalarNode('region')->cannotBeEmpty()->end()
                    ->end()
                ->end()
                ->variableNode('platforms')->end()
                ->booleanNode('debug')->defaultFalse()->end()
                ->scalarNode('topic_arn')->cannotBeEmpty()->end()
            ->end()
        ->end();

        // Here you should define the parameters that are allowed to
        // configure your bundle. See the documentation linked above for
        // more information on that topic.

        return $treeBuilder;
    }
public function getConfigTreeBuilder()
    {
        $treeBuilder = new TreeBuilder('mcfedr_aws_push');

        if (method_exists($treeBuilder, 'getRootNode')) {
            $rootNode = $treeBuilder->getRootNode();
        } else {
            // BC layer for symfony/config 4.1 and older
            $rootNode = $treeBuilder->root('mcfedr_aws_push');
        }

        $rootNode
            ->children()
                ->arrayNode('aws')
                    ->children()
                        ->variableNode('credentials')->end()
                        ->scalarNode('key')->cannotBeEmpty()->setDeprecated('The "%node%" option is deprecated. Use "credentials" instead.')->end()
                        ->scalarNode('secret')->cannotBeEmpty()->setDeprecated('The "%node%" option is deprecated. Use "credentials" instead.')->end()
                        ->scalarNode('region')->cannotBeEmpty()->end()
                    ->end()
                ->end()
                ->variableNode('platforms')->end()
                ->booleanNode('debug')->defaultFalse()->end()
                ->scalarNode('topic_arn')->cannotBeEmpty()->end()
            ->end()
        ->end();

        // Here you should define the parameters that are allowed to
        // configure your bundle. See the documentation linked above for
        // more information on that topic.

        return $treeBuilder;
    }
{@inheritdoc}