bisect = function (a, x, lo, hi) {
    while (lo < hi) {
        var mid = lo + hi >>> 1;
        if (a[mid][1] < x) {
            lo = mid + 1;
        }
        else {
            hi = mid;
        }
    }
    return lo;
}
@param {module:echarts/model/Model}
@return {module:echarts/scale/Time}