请问下如何获取大纲树的树的节点以及监听树形变化的事件

现在看到在OutlinePane中有一个 main = New OutlineMain（）获取的实例中包含了currentTree的节点。

我怎么从外部获取到呢

Start by reading the OutlinePane and OutlineMain implementations, especially how the currentTree instance is created and used. Trace whether the tree nodes or tree-change events are exposed outside those components; done means the supported external access and event-listening path is identified and documented, or the missing API scope is clearly defined.

Written by the indexing model from the issue text.