Node with in a button firing the node event

In the Attached above document when i click the pencil icon. After firing the pencil button clieck event. Immediatly it is firing Node click event. How to stop the Node click event. Please advise

Set e.handled = true;. InputEvent | GoJS API

See also how the “TreeExpanderButton” is defined at

Thanks walter. It worked.

Please remove the image. the data is our security issue