GtkWindow::set_role
Sets the role for the window to role.
The role can be used by the window manager to identify the window in cases where the title is not set or ambiguous. For example a role of "toolbox" will help the window manager identify the window and reposition the window when the user's session is restarted.
This function is only useful on X11, not with other GTK+ targets.
See also: get_role()