final Map<ObjectId, CachedPack> tipToPack = new HashMap<ObjectId, CachedPack>();
final RevFlag inCachedPack = walker.newFlag("inCachedPack");
final RevFlag include = walker.newFlag("include");
final RevFlag added = walker.newFlag("added");
final RevFlagSet keepOnRestart = new RevFlagSet();
keepOnRestart.add(inCachedPack);
walker.setRetainBody(false);
walker.carry(include);
int haveEst = have.size();