if (this.toolTipGenerator != null) {
            if (this.toolTipGenerator instanceof PublicCloneable) {
                PublicCloneable pc = (PublicCloneable) this.toolTipGenerator;
                clone.toolTipGenerator = (CategoryToolTipGenerator) pc.clone();
            }
            else {
                throw new CloneNotSupportedException(
                        "Tool tip generator not cloneable.");