highestbars(src, len, _id) {
        let id = this._tsid(_id, `highestbars(${len})`)
        let high = -Infinity
        let hi = 0
        for (var i = 0; i < len; i++) {
            if (src[i] > high) { high = src[i], hi = i }
        }
        return this.ts(-hi, id, src.__tf__)
    }
Highest value offset for a given number of bars back
@param {TS} src - Input
@param {number} len - Length