Problem with TreeExpanderButton's visibility

Hello,I need help.
I want to hide the TreeExpanderButton by setting its property “visible:false”.But it doesn’t work.
Seems like the TreeExpanderButton is always visible when node has children?

That’s right – the “TreeExpanderButton” already has a Binding of GraphObject.visible depending on Node.isTreeExpanded. See its definition at

Perhaps you want to define your own button by copying to a new name and adapting the “TreeExpanderButton” definition.

Thanks ,walter!
It quite helps.