public void Archive(IRepositoryContext <SongList> ctx, SongList songList, SongListDiff diff, EntryEditEvent reason)
{
var agentLoginData = ctx.CreateAgentLoginData(PermissionContext);
var archived = songList.CreateArchivedVersion(diff, agentLoginData, reason);
ctx.OfType <ArchivedSongListVersion>().Save(archived);
}
