+// TODO(danvk): figure out why the jsdoc has to be copy/pasted from superclass.
+// (I get closure compiler errors if this isn't here.)
+/**
+ * @override
+ * @param {!Array.<Array>} rawData The raw data passed into dygraphs where
+ * rawData[i] = [x,ySeries1,...,ySeriesN].
+ * @param {!number} seriesIndex Index of the series to extract. All other
+ * series should be ignored.
+ * @param {!DygraphOptions} options Dygraph options.
+ * @return {Array.<[!number,?number,?]>} The series in the unified data format
+ * where series[i] = [x,y,{extras}].
+ */
+BarsHandler.prototype.extractSeries = function(rawData, seriesIndex, options) {