public boolean equals(Object obj) {
        if (obj == this) {
            return true;      
        }
        if (!super.equals(obj)) {
            return false;
        }
        if (!(obj instanceof XYAnnotationEntity)) {
            return false;
        }
        XYAnnotationEntity that = (XYAnnotationEntity) obj;
        if (this.rendererIndex != that.rendererIndex) {
            return false;   
        }
        return true;