Please advise what is the best way to proceed.

There is an application on Eto.Forms 2.9.0. On Windows, a WPF backend is used.

It is built on the principle of the SDI interface - multiple equal forms for working with data. MainForm is not set.

When I close the last or only one form - Application.Instance.Terminating is not called. The same thing happens to Application.Instance.Quit().

What is the best way to do it: track the closing of each window and do what on the last one - manually call the code from Terminating, or do something else?