double intValue = dataset.getYValue(series, item);
double mzValue = dataset.getXValue(series, item);
if (dataset instanceof PeakListDataSet) {
PeakListDataSet peakListDataSet = (PeakListDataSet) dataset;
ChromatographicPeak peak = peakListDataSet.getPeak(series, item);
PeakList peakList = peakListDataSet.getPeakList();
PeakListRow row = peakList.getPeakRow(peak);
String tooltip = "Peak: " + peak + "\nStatus: "
+ peak.getPeakStatus() + "\nPeak list row: " + row
+ "\nData point m/z: " + mzFormat.format(mzValue)