public boolean equals(Object obj) {

        if (obj == this) {
            return true;
        }

        if (!(obj instanceof StandardContourToolTipGenerator)) {
            return false;
        }
        StandardContourToolTipGenerator that 
            = (StandardContourToolTipGenerator) obj;
        if (this.valueForm != null) {
            return this.valueForm.equals(that.valueForm);
        }
        return false;