The attention tab property

tabs.Tab describes it:

Indicates whether the tab is drawing attention. For example, when the tab displays a modal dialog, attention will be true .

Off the top of my head, another reliable way to see it in action is when a browser receives a tab sent from another device.

My question: is there no way to set this property via API? The attention state could be quite helpful in certain cases.

Update: If not, how does one go about requesting an API?