public Change <TDest> OfType <TDest>() where TDest : class { return(new Change <TDest> { Modified = Modified?.OfType <TDest>().ToList(), Added = Added?.OfType <TDest>().ToList(), Removed = Removed?.OfType <TDest>().ToList(), NotModified = NotModified?.OfType <TDest>().ToList(), }); }