I have a symfony bundle working on Symfony 3 and 4. But Since Symfony 5, the method define configuration inside TreeBuilder has changed: Deprecated tree builders without root nodes.
From this
$treeBuilder = new TreeBuilder();
$rootNode = $treeBuilder->get('bundle_name');
To this
$treeBuilder = new TreeBuilder('bundle_name');
$rootNode = $treeBuilder->getRootNode();
Since I want my bundle to work from Symfony 3 and Symfony 5, how can I change the TreeBuilder to work in all the cases?