public void setDataset(WaferMapDataset dataset) {
        // if there is an existing dataset, remove the plot from the list of 
        // change listeners...
        if (this.dataset != null) {
            this.dataset.removeChangeListener(this);
        }

        // set the new dataset, and register the chart as a change listener...
        this.dataset = dataset;
        if (dataset != null) {
            setDatasetGroup(dataset.getGroup());
            dataset.addChangeListener(this);
        }

        // send a dataset change event to self to trigger plot change event
        datasetChanged(new DatasetChangeEvent(this, dataset));