How to get a property name in a global event

[2mik]

Hello,
Thank you for your work.
I would like to use global events as written in the manual

pane.on('change', (ev) => {
  console.log('changed: ' + JSON.stringify(ev.value));
});

How to retrieve the name of the object property that was changed?
In a console I get

I'd prefer to use global events rather than binding events because bindings are changed when a user select another object to edit.