public function getConfigTreeBuilder()
{
$treeBuilder = new TreeBuilder();
$rootNode = $treeBuilder->root('jwt_auth');
$rootNode->children()->scalarNode('client_id')->isRequired()->cannotBeEmpty()->end()->scalarNode('client_secret')->isRequired()->cannotBeEmpty()->end()->scalarNode('domain')->defaultValue('')->end();
return $treeBuilder;
}