private void connectInternal(String name, Mongo mongo) {
_buildInfo = initBuildInfo(mongo);
_db = mongo.getDB(name);
_counter = new MongoDBVCounter(_db);
_tree = new Tree(_db);
//create root commit and master branch if needed
if (_tree.isEmpty()) {
Commit root = new Commit(_counter.getNextId(), 0, 0,
Collections.<String, IdMap>emptyMap());