public function getConfigTreeBuilder()
{
$treeBuilder = new TreeBuilder();
$rootNode = $treeBuilder->root('oauth2');
$rootNode->children()->scalarNode('driver')->defaultNull()->end()->scalarNode('user_provider')->defaultNull()->end()->arrayNode('model')->prototype('scalar')->end()->end()->arrayNode('response_handler')->prototype('scalar')->end()->end()->arrayNode('grant_handler')->prototype('scalar')->end()->end()->arrayNode('token_handler')->prototype('scalar')->end()->end()->arrayNode('resource_handler')->prototype('scalar')->end()->end()->end();
return $treeBuilder;
}