message: adjust getBBox polyfill logic
diff: // SVGGElement.prototype.getBBox to calculate boundaries.
  // JSDOM doesn't support this: https://github.com/jsdom/jsdom/issues/1664
  class GetBBoxPolyfill {
  + static exists(): boolean {
  + // @ts-ignore
  + return typeof window.Element.prototype.getBBox !== 'undefined';
  + }
  +
  static create(
  x: number = 0,
  y: number = 0,
  width: number = 1000,
  height: number = 500,
  - ) {
  + ): void {
  + if (this.exists()) {
  + return;
  + }
  +
  Object.defineProperty(window.Element.prototype, 'getBBox', {
  writable: false,
  value: () => ({ x, y, width, height }),
  });
  }
  - static remove() {
  + static remove(): void {
  + if (!this.exists()) {
  + return;
  + }
  +
  // @ts-ignore
  delete window.Element.prototype.getBBox;
  }
  