public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        }
        if (!(obj instanceof RingPlot)) {
            return false;
        }
        RingPlot that = (RingPlot) obj;
        if (this.separatorsVisible != that.separatorsVisible) {
            return false;
        }
        if (!ObjectUtilities.equal(this.separatorStroke, 
                that.separatorStroke)) {
            return false;
        }
        if (!PaintUtilities.equal(this.separatorPaint, that.separatorPaint)) {
            return false;
        }
        if (this.innerSeparatorExtension != that.innerSeparatorExtension) {
            return false;
        }
        if (this.outerSeparatorExtension != that.outerSeparatorExtension) {
            return false;
        }
        if (this.sectionDepth != that.sectionDepth) {
            return false;
        }
        return super.equals(obj);