renderDataPoints (options) {
        if (!arguments.length) {
            return {
                fillOpacity: this._dataPointFillOpacity,
                strokeOpacity: this._dataPointStrokeOpacity,
                radius: this._dataPointRadius
            };
        } else if (!options) {
            this._dataPointFillOpacity = DEFAULT_DOT_OPACITY;
            this._dataPointStrokeOpacity = DEFAULT_DOT_OPACITY;
            this._dataPointRadius = null;
        } else {
            this._dataPointFillOpacity = options.fillOpacity || 0.8;
            this._dataPointStrokeOpacity = options.strokeOpacity || 0.0;
            this._dataPointRadius = options.radius || 2;
        }
        return this;
    }
Always show individual dots for each datapoint.

If `options` is falsy, it disables data point rendering. If no `options` are provided, the
current `options` values are instead returned.
@example
chart.renderDataPoints({radius: 2, fillOpacity: 0.8, strokeOpacity: 0.0})
@param  {{fillOpacity: Number, strokeOpacity: Number, radius: Number}} [options={fillOpacity: 0.8, strokeOpacity: 0.0, radius: 2}]
@returns {{fillOpacity: Number, strokeOpacity: Number, radius: Number}|LineChart}