textEditingTool accept on enter behaviour doesn'

https://github.com/NorthwoodsSoftware/GoJS/blob/master/samples/customTextEditingTool.html example suppose to react to user pressing enter but apparently

tool.acceptText(go.TextEditingTool.Enter);

doesn’t do anything. I was expecting same behaviour as

tool.acceptText(go.TextEditingTool.Tab);

That depends on the edited TextBlock.isMultiline value.
If it’s true it’s expected to allow entry of newlines into the text string.