alwaysUseRounding (alwaysUseRounding) {
        if (!arguments.length) {
            return this._alwaysUseRounding;
        }
        this._alwaysUseRounding = alwaysUseRounding;
        return this;
    }
Set or get whether rounding is enabled when bars are centered. If false, using
rounding with centered bars will result in a warning and rounding will be ignored.  This flag
has no effect if bars are not {@link BarChart#centerBar centered}.
When using standard d3.js rounding methods, the brush often doesn't align correctly with
centered bars since the bars are offset.  The rounding function must add an offset to
compensate, such as in the following example.
@example
chart.round(function(n) { return Math.floor(n) + 0.5; });
@param {Boolean} [alwaysUseRounding=false]
@returns {Boolean|BarChart}