public void ChangeWindow(Window newWindow)
{
if (_toplevel == null)
{
var errorMessage = "Couldn't change window. TopLevel view doesn't exist.";
_logger.Fatal(errorMessage);
throw new InvalidOperationException(errorMessage);
}
_toplevel.RemoveAll();
_toplevel.Add(newWindow);
_currentWindow = newWindow;
_toplevel.LayoutSubviews();
_toplevel.FocusFirst();
}