title: JFreeChart - How do I translate domain crosshair value to a TimeSeriesDataItem
body: <p>I have an XYPlot displaying multiple TimeSeries in a TimeSeriesCollection. I'd like to be able to get the list of TimeSeriesDataItems that correspond to a domain crosshair click. </p>
  
  <p>It looks like I can add a PlotChangeListener to be notified of a change in the crosshair value and I can then call XYPlot.getDomainCrosshairValue(), but I can't see how to then use that crosshair value to get the right time series items</p>