public PieChartData setHasLabelsOnlyForSelected(boolean hasLabelsOnlyForSelected) {
        this.hasLabelsOnlyForSelected = hasLabelsOnlyForSelected;
        if (hasLabelsOnlyForSelected) {
            this.hasLabels = false;
        }
        return this;
    }
Set true if you want to show value labels only for selected value, works best when chart has
isValueSelectionEnabled set to true {@link Chart#setValueSelectionEnabled(boolean)}.
hellocharts-library/src/lecho/lib/hellocharts/model/PieChartData.java