public Line setHasLabels(boolean hasLabels) {
        this.hasLabels = hasLabels;
        if (hasLabels) {
            this.hasLabelsOnlyForSelected = false;
        }
        return this;
    }
Set area transparency(255 is full opacity) for filled lines

@param areaTransparency
@return
hellocharts-library/src/lecho/lib/hellocharts/model/Line.java