   return lbb;
    }

    function insertBestBackwardBranch(type, threshold, maxThreshold) {
        var branches = [];
        var quanta = track.analysis[type];
        for (var i = 0; i < quanta.length; i++) {
            var q = quanta[i];
            for (var j = 0; j < q.all_neighbors.length; j++) {
                var neighbor = q.all_neighbors[j];

                if (neighbor.deleted) {
                    continue;
                }

                var which = neighbor.dest.which;
               